The effect of a heavier weight bullet?


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BruceRDucer
August 26, 2008, 11:18 PM
/


The effect of a heavier weight bullet?

Is: (1) Less recoil? (2) More Recoil?

(3) There's more to it.

:uhoh:

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esmith
August 26, 2008, 11:27 PM
The effect of a heavier weight bullet?

Is: (1) Less recoil? (2) More Recoil?

(3) There's more to it.

As a general rule, the heavier the bullet, the more recoil you will feel. There are more factors that influence felt recoil, barrel length, gun weight, etc.

One of the Newton laws state that every reaction has you know the equal opposite reaction. Therefore something with more mass will have more momentum, or drag going in both directions, than something with less mass. I think.

If you want another example take a medicine ball and throw it away from your chest and notice the force pushing you backwards. Then take a ping pong ball or something lighter and do the same thing. You will notice a HUGE difference in backwards momentum pushing you back with the medicine ball than something lighter. I suppose you can say there is more recoil with the medicine ball if you were to try and describe it in terms of firearms.

Im not a physics professor so don't call me out on using wrong terms or whatever.

General Geoff
August 26, 2008, 11:28 PM
(3) there's more to it.

You have to weigh bullet weight and velocity, and especially the mass of the gun, as well as to a lesser extent powder burn rates to really determine relative recoil.

Sylvan-Forge
August 27, 2008, 02:51 AM
Here's a formula for 'Recoil Energy' :

Recoil energy in foot-pounds (ft-lbs) =

(Pw x Vp + 4700 x Cw)^2
.........64.348 x Fw

Pw = Projectile weight in pounds. (Divide grains by 7000).

Vp = Velocity of projectile at the muzzle in feet per second.

Cw = Charge (powder) weight in pounds. (Divide grains by 7000).

Fw = Firearm weight in pounds.



Example :
124 grain bullet/7000 = 0.0177
1095 f/s muzzle V
4.6 grains of powder/7000 = 0.00066
2.1 lb. pistol


(0.0177 x 1095 + 4700 x 0.00066)^2
..............64.348 x 2.1

=

(19.3815 + 3.102)^2
........135.1308

=

505.508
135.1308

=

3.7409 ft-lbs of recoil


.

jakemccoy
August 27, 2008, 03:04 AM
Muzzle energy is the most important factor for perceived recoil. While heavier bullets may have more momentum, heavier bullets of the same caliber and same gun tend to have less muzzle energy. Less muzzle energy typically translates into less perceived recoil.

Analyze your physics equations. Better yet, just go out to the range and experiment. You'll see.

Ridgerunner665
August 27, 2008, 03:05 AM
As a general rule...all other factors being equal (gun weight)

The more weight that you're pushing through the barrel (bullet and powder), the more recoil you get.

Sylvan-Forge
August 27, 2008, 03:26 AM
'Felt Recoil' can be quite subjective.

Several factors to include the time it takes the projectile to leave the muzzle, pressure curve, how the firearm fits the shooter, bore axis, wrist/hand strength, musculo-skeletal geometry and weight of shooter all factor in.

One shooter may find a fast 95gr 9mm bullet recoils more than a slower 147gr
one does while another may 'feel' the opposite way, even though the muzzle and recoil energies may be near the same.


Often you will hear reported that the fast/light high pressure snaps while the slow/heavy low pressure shoves.

YMMV.

.

loop
August 27, 2008, 05:39 AM
Recoil is the least important factor in choosing a heavier bullet over a lighter bullet.

If recoil in a given caliber is a problem then you need to choose another caliber.

Ballistic coefficient, sectional density and velocity are much more important factors.

Ballistic coefficient is the bullets ability to cut through the air (as brief as I can make it). Sectional density determines its ability to hold together on contact.

In general heavier bullets have higher coefficients and more sectional density that lighter bullets. They also, at longer ranges, have better trajectories.

Further, in handguns especially, heavier bullets hit higher on the target at shorter ranges than lighter bullets. Lighter bullets also fall off the chart much faster at longer ranges. IOW, they lose their velocity more quickly.

Also, because the sectional density (length of the bullet) is longer in heavier bullets there is more surface area in contact with the rifling, which improves accuracy.

These are the factors to consider when looking at bullet weight. Recoil shouldn't be a factor.

dogma512
August 27, 2008, 07:06 AM
Many people feel that the subjective recoil of heavier bullet weights in the same caliber is more manageable. This has been my experience as well.

200gr .40 slugs are very popular with limited class USPSA shooters that want to make major power factor (which is essentially calculated as momentum with funky units) but still have the most controllable recoil possible.

bogie
August 27, 2008, 09:28 AM
Here's a formula for 'Recoil Energy'

Strikes me as being one of "those" formulas...

It assumes I have the same recoil from 42 grains of 4350 in my .308 as I would with 42 grains of AA2230.

Vern Humphrey
August 27, 2008, 09:31 AM
Muzzle energy is the most important factor for perceived recoil.
Momentum is the most important factor in recoil. The momentum of the ejecta (bullet and powder) equals the momentum of the gun.

jakemccoy
August 27, 2008, 01:09 PM
Momentum is the most important factor in recoil. The momentum of the ejecta (bullet and powder) equals the momentum of the gun.

You may be talking about comparing different weights of different calibers. For most people, muzzle energy is the most important factor when comparing different bullet weights of the same caliber, same brand, same gun. If we were to go out to the range and compare the different weights of .40 caliber bullets from Double Tap, I'm confident that 99 out of 100 people would say 135 gr has substantially more felt recoil than the 180 gr. It's not even close.

Vern Humphrey
August 27, 2008, 01:58 PM
Originally Posted by Vern Humphrey
Momentum is the most important factor in recoil. The momentum of the ejecta (bullet and powder) equals the momentum of the gun.
You may be talking about comparing different weights of different calibers. For most people, muzzle energy is the most important factor when comparing different bullet weights of the same caliber, same brand, same gun.
We're talking about recoil. The key element in recoil is momentum.

jakemccoy
August 27, 2008, 02:36 PM
We're talking about recoil. The key element in recoil is momentum.

Actually, we're talking about perceived recoil at the range, not recoil derived from physics equations. I guess you just want to ignore actual experiments at the range with different weights of the same caliber, same brand, same gun.

Vern Humphrey
August 27, 2008, 02:43 PM
Actually, we're talking about perceived recoil at the range, not recoil derived from physics equations. I guess you just want to ignore actual experiments at the range with different weights of the same caliber, same brand, same gun.
If we're talking about perceived recoil from the same gun, then momentum is clearly the calculation we want.

From the same gun a load that generates more momentum will be perceived as having more recoil than a load that generates less.

sqlbullet
August 27, 2008, 02:58 PM
Bruce, as is indicated in the thread, there is more too it.

However, utilizing a simple scenario, we can assume the only change is the weight of the bullet. We have a 'magic' powder that always produces the same velocity from a given charge regardless of projectile mass. We assume we are using the same gun, and all other forces are negligible.

Recoil is due to Newtons Third Law -"All forces occur in pairs, and these two forces are equal in magnitude and opposite in direction." In this case we are talking about the preservation of momentum.

momentum = mass X velocity

Therefore, as mass increases, so does momentum. The paired force to the momentum of the bullet (and expelled charge) is recoil, and it must be equal and opposite. Since the gun and all other variables in our simple example are the same, free recoil must increase.

As Jakemccoy has pointed out, lighter bullets tend to produce more kinetic energy than heavier bullets. However, this does not translate to more free recoil, since as Vern Humphrey correctly states, recoil is preservation of momentum, not energy.

kinetic energy = 1/2 mass * velocity^2

As you can see, the formula for energy is heavily weighted to velocity, since it's input has a geometric increase on the output. Therefore, smaller bullets will generate more energy as there velocity has a huge impact.

You can evaluate yourself easily how much a bullet weight change will affect free recoil, if you know the velocity. For instance, using Double Tap data for 10mm (yes, I am one of those guys):

135 grain bullet at 1600 fps = 216000 grain feet/second
230 grain bullet at 1120 fps = 257600 grain feet/second

The 230 grain bullet will generate 19.3% more free recoil than the 135 grain bullet in these loads. ((257600-216000)/216000 = .19259...)

Perception of free recoil is a matter of psychology, ergonomics and kinesiology. Each person decelerates the weapon at a different rate. The longer it takes you to slow the weapon, the less percieved work is done (like using a hoist to raise a motor, same work, over a much longer period means it feels lighter).

jakemccoy
August 27, 2008, 03:16 PM
My experiments clearly indicate that energy is the culprit.

For normal people in the real world...

Perceived Recoil = How much the bang makes you want to say, "Whoa, I can't quite control that."

Again, I'm talking about different weights with the same caliber, same brand, same gun.

Vern Humphrey
August 27, 2008, 03:27 PM
My experiments clearly indicate that energy is the culprit. We'll have to agree to disagree.
Your experiments are incorrect. Recoil is a factor of conservation of momentum, not conservation of energy.
Consider this; A .220 Swift firing a 55 grain bullet at 4000 fps develops 1942 ft lbs of muzzle energy. A .45-70, firing a 405 grain bullet at 1300 fps only develops 1518 ft lbs of energy.

Yet the .45-70 kicks a lot harder!

jakemccoy
August 27, 2008, 03:34 PM
Vern,

It sounds like you have no experiment with same caliber, same brand, same gun. If I were answering a question on a physics exam, I'd say momentum is the culprit. In the real world, the following definition is easier to grasp...

Perceived Recoil = How much the bang makes you want to say, "Whoa, I can't quite control that."

Put down the equations for a second. Go out and buy different weights of the same caliber from Double Tap. Then, let a friend shoot the rounds from the same gun without clouding your friend's mind. Ask your friend which bullet has "more recoil." My money goes on the lighter bullet. Of course, you're also free to just give me your money from such a bet.

-Jake

jakemccoy
August 27, 2008, 03:44 PM
However, utilizing a simple scenario, we can assume the only change is the weight of the bullet. We have a 'magic' powder that always produces the same velocity from a given charge regardless of projectile mass. We assume we are using the same gun, and all other forces are negligible.


I hope you realize that scenario doesn't really exist in the real world with the same caliber, same brand, same gun.

MTMilitiaman
August 27, 2008, 03:51 PM
jakemccoy

He's mistaking actual recoil for perceived recoil. You're mistaking theory for fact.

Actual recoil is relatively simple to calculate and as mentioned, relies primarily on momentum.

Perceived recoil is quite a bit more subjective. Some people prefer a slower recoil impulse, even if it involves disruption of more recoil forces. Others prefer a sharper recoil impulse. Stock shape also affects perceived recoil. As an example, I've introduced several new shooters, and my experiments have led me to the opposite conclusion regarding perceived recoil--energy is the least important factor, and the average shooter will be more impressed by how much the gun moves them, which is almost solely determined by momentum.

Vern Humphrey
August 27, 2008, 03:53 PM
Go out and buy different weights of the same caliber from Double Tap.
What makes you think I haven't done that?

I have loaded .45 ACP in every weight from 165 to 230 grains. I've done the same with .45 Colt, but gone up to 300 grains. I've done that with many other cartridges.

In the same gun, the load that develops more momentum will produce more perceived recoil -- even if kinetic energy is actually lower.

jakemccoy
August 27, 2008, 03:55 PM
We're proving that perceived recoil is based on the individual.

BruceRDucer
August 27, 2008, 03:57 PM
Thanks all for responding.

So according to what has generally been affirmed, (but not always in every scenario) if I shoot a 30-06 rifle (the actual case) with a 150 grain bullet, chances are that I might "perceive" more recoil than with a 180 grain bullet?

But people are also saying that this perception of recoil can be affected by velocity, and probably the physical characteristics of the rifle, such as its WEIGHT, BARREL LENGTH, BARREL DIAMETER, etc?

:)

As I understand this, it is also being said that a heavier 180 grain round, can CONSERVE the MOMENTUM, thus producing significant recoil that way as well. Is this the general idea? That it isn't as simple as some like to think?

/

Vern Humphrey
August 27, 2008, 04:05 PM
We're proving that perceived recoil is based on the individual.

To some extent. Shooter A may find a certain gun and cartridge unpleasant to fire, and Shooter B will not be bothered by it.

But if we change the load to produce less momentum (even if kinetic energy goes up), both will agree it "kicks less."

jakemccoy
August 27, 2008, 04:15 PM
Vern, I will agree to disagree.

jakemccoy
August 27, 2008, 04:18 PM
Thanks all for responding.

So according to what has generally been affirmed, (but not always in every scenario) if I shoot a 30-06 rifle (the actual case) with a 150 grain bullet, chances are that I might "perceive" more recoil than with a 180 grain bullet?

But people are also saying that this perception of recoil can be affected by velocity, and probably the physical characteristics of the rifle, such as its WEIGHT, BARREL LENGTH, BARREL DIAMETER, etc?



As I understand this, it is also being said that a heavier 180 grain round, can CONSERVE the MOMENTUM, thus producing significant recoil that way as well. Is this the general idea? That it isn't as simple as some like to think?

It's quite simple. Put down the equations. Go out to the range and experiment with the same caliber, same brand, same gun. Theory is important for acing your physics exam. Theory has less importance for this particular issue.

rcmodel
August 27, 2008, 04:31 PM
Lets look at a 30-06 factory loads.
8 pound scope & rifle.
50 grains powder.

150 grain @ 2910 FPS.
Recoil Impulse in (lbs sec) = 2.82
Velocity of recoiling firearm (fps) = 11.37
Free recoil energy in (ft/lbs) = 16.05

180 @ 2,700 FPS
Recoil Impulse in (lbs sec) = 3.04
Velocity of recoiling firearm (fps) = 12.25
Free recoil energy in (ft/lbs) = 18.64



And .40 S&W factory loads:
2 pound gun
7 grains powder

165 @ 1,060 FPS
Recoil Impulse in (lbs sec) = 0.90
Velocity of recoiling firearm (fps) = 14.49
Free recoil energy in (ft/lbs) = 6.52

180 grain bullet
Recoil Impulse in (lbs sec) = 0.93
Velocity of recoiling firearm (fps) = 14.99
Free recoil energy in (ft/lbs) = 6.97

The heavy bullet clearly kicks harder & faster then the light bullet.

That will be so in any caliber, in any gun, if both bullet weights are loaded to the full velocity possible in the caliber.

rcmodel

jakemccoy
August 27, 2008, 04:41 PM
rcmodel,

I don't know of any brand that posts higher energy for a heavier bullet in the same caliber. From where are those numbers?

-Jake

rcmodel
August 27, 2008, 04:43 PM
I don't know of any posted bullet energy figure that will move as much weight one foot on impact as it says it should either!

For instance, a 44 Mag should knock a Harley-Davidson off it's kick-stand, but it won't!
In fact, it would barely make it wiggle!

Bullet energy figures aren't all they are cracked up to be when the metal meets the meat!

Recoil calculator:
http://www.handloads.com/calc/recoil.asp

rcmodel

Vern Humphrey
August 27, 2008, 04:47 PM
I don't know of any brand that posts higher energy for a heavier bullet in the same caliber.
By and large, you're correct. Because Kinetic Energy increases with the square of the velocity, while momentum is a linear function, small decreases in bullet mass resulting in small increases in velocity will usually yield higher KE numbers.

Vern Humphrey
August 27, 2008, 04:49 PM
For instance, a 44 Mag should knock a Harley-Davidson off it's kick-stand, but it won't!
I hope that's your Harley you're shooting at, and not mine.:p

You're correct, of course. What moves the Harley is momentum, not Kinetic Energy. And pistol cartridges don't develop all that much momentum.

rcmodel
August 27, 2008, 05:07 PM
Neither do rifles, in the grand scheme of things that go boom.

Even a .460 Weatherby won't knock that Harley over with 8,000+ ft/lb of energy!

But it will sure kick the snot out of you!

rcmodel

Vern Humphrey
August 27, 2008, 05:09 PM
Before you touch that cannon off, let's make sure it's not my Harley down-range.:p

rcmodel
August 27, 2008, 05:12 PM
I was just using it as an example.

I wouldn't really shoot your Harley! :D

But, come to think of it, I did have one once that somebody should have shot & put it out of it's misery! :banghead:

rcmodel

Vern Humphrey
August 27, 2008, 05:28 PM
Glad to hear it.

Now if it's a horse you want to shoot, I have one that did something today to deserve it.:D

1911Tuner
August 27, 2008, 06:13 PM
Sorry Jake...Vern's gotcha on this one.

Lemme see if I can 'splain it a little betta.

A heavier bullet resists acceleration more than a light one, and thus requires a greater magnitude of force to get it moving.

In a handgun, the greatest percentage of bullet velocity and recoil...call it energy or momentum or fairy dust if you want...is generated in the first half inch or so of bullet travel during the transition from static to peak pressure. Peak pressure being the moment of maximum force applied. Once the pressure...and the force applied have peaked...they start to drop rapidly.

Refer to Newton 1B. Objects in motion rend to remain in motion. This is called Conservation of Momentum, and so the bullet will continue to accelerate with less force applied than it required to get it moving in the first place.

Refer to Newton 1A. Objects at rest tend to remain at rest...and the faster you try to make them move, the more they resist...the "heavier" they become, for lack of a better description. This is known as inertia. You can lift a 100-pound barbell off the floor at a rate of one foot per minute fairly easily. Try to make it move at 10 feet per second, and it becomes a whole 'nother ball game.

Because the heavy bullet resists acceleration harder than a lighter bullet...more force must be applied during the initial bump, while the pressures...and forces...are rapidly and violently climbing toward peak.

Because force forward equals force backward...here is where almost all the felt recoil will occur, and very little will be generated after that point...even though the bullet is still accelerating. Because it all happens in a handful of milliseconds, your brain doesn't have time to process and recognize the tiny amount of added "push" after the initial punch, and you perceive it as one, sudden impulse.

His analogy with the .22 centerfire and the .45-70 is valid, and one that I've used a lot to explain it. A 50-grain bullet at 4,000 fps will generate a very mild recoil level. The .48 caliber 405 grain bullet at 1350 fps will kick your eye teeth out...in rifles of equal weight. This, even though the zippy .22's kinetic energy is higher than that of the lumbering .46 caliber slug.

jakemccoy
August 27, 2008, 06:16 PM
...more theory.

You'll have to take my word for it that I don't need an explanation on theory. If you want to be on the same page as me, read my posts. Otherwise, please don't include me in your discussion. I mean that in the nicest possible way.

Vern Humphrey
August 27, 2008, 06:47 PM
Then what point are you trying to make?

You seem to reject the idea that in the same gun a load that generates more momentum will result in more perceived recoil. Is that a fair statement of your position?

And if so, how do you explain it?

jakemccoy
August 27, 2008, 06:48 PM
What point am I trying to make?

Read my posts, maybe a little slower.

Vern Humphrey
August 27, 2008, 06:53 PM
What point am I trying to make?

Read my posts, maybe a little slower.
I have -- which is why I ask.

Now I asked a simple question -- can you answer it yes or no?

jakemccoy
August 27, 2008, 07:03 PM
You seem to reject the idea that in the same gun a load that generates more momentum will result in more perceived recoil. Is that a fair statement of your position?

There's no need to make a statement of my position when I've already given my own explanation in simple enough terms.

One more time...

Perceived recoil in the real world = How much the bang makes you want to say, "Whoa, I can't quite control that."

A heavier bullet from the same brand, same caliber, same gun, will typically have less muzzle energy and less perceived recoil. That's the result of my experiments with .40 caliber bullets from a handgun. Sometimes, theory takes a back seat to experimentation for a particular issue at hand.

Vern Humphrey
August 27, 2008, 07:15 PM
You've never compared a 200 grain load from my Ruger Blackhawk in .45 Colt with a 300 grain load from the same gun.

Note that Cowboy Action shooters, who are not constrained by "power levels" tend to use lighter, not heavier bullets to give less perceived recoil.

jakemccoy
August 27, 2008, 07:28 PM
You've never compared a 200 grain load from my Ruger Blackhawk in .45 Colt with a 300 grain load from the same gun.

Note that Cowboy Action shooters, who are not constrained by "power levels" tend to use lighter, not heavier bullets to give less perceived recoil.

How do the muzzle energies compare?

You're right that I've never tried those particular loads. Likewise, you've never compared the Double Tap .40 caliber 180 gr to the 135 gr. It's commonly known that people will avoid that particular 135 gr because the damn thing is too hot.

Anyway, the loads you mentioned are irrelevant for me because that's not the gun I carry, get it? The real world for each particular shooter is the only thing that really matters here.

You can present a theoretically correct explanation in a video with high definition and surround sound. If what you're saying is irrelevant to the guns and ammo of the original poster, then you're providing a disservice.

gizamo
August 27, 2008, 07:44 PM
Hmmmmm,

I liked the 45/70 analogy...
What if we acheived the same muzzle velocity with the same bullet weight but substituted a Black Powder 'load for a fast burning smokeless powder. Wouldn't we acheive the same bullet performance with a major change in felt recoil?

giz

1911Tuner
August 27, 2008, 08:06 PM
Dunno 'bout that, Giz...but I do know that a .220 Swift, drivin' a 50-grain bullet wide open will push it to about 4,000 fps, and generate more kinetic energy than the old .45-70-405 round. You can fire an 8 pound groundhog rifle with the butt against your chin without any great discomfort or lasting effects. I wouldn't suggest tryin' that with my 8-pound Sharps carbine, though...unless you're into pain and wires in your jaw and oral surgery.

Vern Humphrey
August 27, 2008, 08:15 PM
What if we acheived the same muzzle velocity with the same bullet weight but substituted a Black Powder 'load for a fast burning smokeless powder. Wouldn't we acheive the same bullet performance with a major change in felt recoil?
Yep -- because the black powder charge is heavier, and the powder is part of the ejecta.

1911Tuner
August 27, 2008, 08:21 PM
Yep -- because the black powder charge is heavier, and the powder is part of the ejecta.

Yep. Goin' back to the .45-70 round...you can get about the same velocity with 40 grains of IMR 3031 as you can with 70 grains of black powder...or perhaps a little more.

So, add the powder's mass to the bullet's. That would put the mass/weight of the ejectiva at 475 grains...and now you're gettin' into serious recoil.

Vern Humphrey
August 27, 2008, 08:25 PM
Like the man said, you wouldn't want to rest the butt on your chin and light that puppy off.

gizamo
August 27, 2008, 09:32 PM
Agree with most everything except one thing. Using the BP example, there is a difference in the peak pressure. It is not as rapid as with the smokeless. Granted the same energy is expanded. But the pressure is not peaking as rapidly....

And the felt recoil feels reduced. More of a hard shove then a sharp snap....

Giz

Sylvan-Forge
August 27, 2008, 09:42 PM
bogie,
It does account for velocity changes in the equation .. I guess you mean the lack of factoring the pressure curve?

rcmodel,
Could you post the formula you used?

.

Sylvan-Forge
August 27, 2008, 10:08 PM
....oops

230RN
August 27, 2008, 10:22 PM
This is very sad to watch.

35 Whelen
August 27, 2008, 10:41 PM
Very interesting discussion, fellows! The 220 Swift vs. 45-70 is a perfect analogy regarding recoil where it relates to muzzle energy. (On a side note, this comparision, in my opinion, should be read by people who like to use bullet energy as a factor in determining how well said bullet will kill.)

A heavier bullet from the same brand, same caliber, same gun, will typically have less muzzle energy and less perceived recoil. That's the result of my experiments with .40 caliber bullets from a handgun. Sometimes, theory takes a back seat to experimentation for a particular issue at hand.

This is a very easy argument to solve. Fetch your favorite 12 ga. shotgun and stoke it with a standard velocity (1200 fps) 1 oz. trap load. Shoot it and take note of the recoil. Now, stoke the same shotgun with a 1 1/2 oz. turkey load and touch that puppy off again. If you feel no difference in the recoil of these two, I'll eat your socks without ketchup!

I think what the guys like jakemccoy are feeling with the lighter bullets is recoil velocity. That's supposedly the stuff that makes rifles chambered for cartridges like the 300 Weatherby so painful to shoot. A close friend of mine has told me he 10 times rather shoot a 338 Win Mag than a 300 Win Mag. He says the recoil of the larger is more of a roaring push, while that of the smaller is a very sharp, painful slap. I tend to agree. I own a 358 Norma, and though the recoil is substantial, it's certainly not all that bothersome.

I understand jakemccoy's assertion as I've experienced this with my Ruger Security Six 357 Mag. I've fired bullets as heavy as 170 gr. @ too many fps (handloads).:o The recoil out of the 4" barreled pistol was substantial for the caliber, but not unbearable. On the other hand, I had some Remington factory loaded ammo with 125 gr. bullets. :what: WOW!! Talk about unpleasant!! When I fired those things, a fireball formed at the muzzle, the grip soundly slapped the palm of my hand, and the muzzle snapped erect as the entire pistol wrenched in my hand in a direction opposite of the twist of the rifling. And if I'm not mistaken, this load, at least at the time had the highest muzzle energy of any 357 load. I fired a friends 475 Linebaugh and honestly found it far less disconcerting with its roar and comparitively slow muzzle rise.
Another 2.....
35W

cliffy
August 27, 2008, 11:18 PM
A .243 Winchester issues forth a 100 grain bullet @ 3000 to 3150 fps safely, with correct powder burn rates. Reasonable recoil (14 ft/lbs of recoil) aides ACCURACY by not flinching. Flinching induces trigger jerk and a miss is as good as any miss, for any reason. Crying "FLYER" is not a hunting option. LIGHTEN UP and hit the target 10x, is my philosophy.

Hydrostatic shock produced from extreme velocity hits is a real-world scenario. Rump and stomach shots produce the need for great tracking skills. When a bullet leaves the muzzle at under 3000 feet per second, it best be RIGHT-on-TARGET. Slamming a whitetail with a 170 grain .30/30 bullet will make one a believer in that caliber, if the hit is within the shoulder area, but too far back will make one falsely think a stronger caliber is required. Target shooting regularily has no substitute, for bringing home some great-tasting steaks instead of trailing blood for miles. Cliffy

BruceRDucer
August 28, 2008, 05:26 AM
/

Okay, so what everyone is telling me is that if I'm going to sight in a 30-06 rifle, I need to get a Harley.

If the Harley gets knocked down, there was more recoil.

If the Harly does not get knocked down, there was less recoil. :uhoh::uhoh::uhoh:

----------------------------------------------------

It has been basically informative though. I sort of guessed that a heavier grain bullet would induce a slower velocity and mild recoil; but now I understand that the heavier bullet will generate a stronger recoil, amounting to several more pounds of force.

___________________________________

Next question:

A couple dozen rounds of 30-06 ammo, in 147 grain came to me with the rifle.

The ammo was bought at a gun show. (not by me)

Would you shoot the ammo? It's a guess of course, but would you? Or would you just set it aside or toss it away?

I haven't a clue who loaded it. Nor have I any idea what is inside.

Frankly, I'd just as soon toss it away.

/

Phil DeGraves
August 28, 2008, 10:09 AM
Heavy bullets produce more recoil in the same caliber, same gun, than lighter bullets. Not theory but fact.
I've shot many different bullet weights in all of my guns and this is the truth every time.

There are none so blind as those that will not see.

1911Tuner
August 28, 2008, 10:40 AM
I think a lot of what a given shooter perceives as recoil energy with a light/fast bullet...or however you want to describe it...is due to the increased muzzle blast and concussion. It's a sensory overload that's difficult for the human brain to process and separate. Tied in is the fact that many loaders and/or manufacturers use a slow powder in order to achieve the top-end velocities attainable in a given platform only adds to the effect.

I liken it to my old hot-rod days. Joe would get himself a new Mustang or Camaro or Challenger...and immediately lop the exhaust system off just back of the headpipes, and clamp on a pair of Cherry Bombs or Thrush glass packs.

(And I just dated myself.) :)

The car was loud with a capital L. His perception was that the car was faster...making more power because of the freer-flowing exhaust. He swore it was faster. He could feel it pulling harder, yadda yadda.

The problem was that...when he hooked'em up with his buddy that he'd raced a dozen times, or took it to the strip...the reality was that the car wasn't one bit faster, and may have even slowed down a bit.

But...because it SOUNDED like it was oozing more raw horsepower reckoned in the hundreds above what it produced before the hack job...he just knew it was faster, and even when the timing tower at the local dragstrip disproved his theoiry...he remained in denial.


So, the questions loom:

Can we drive a 185-grain bullet so hard that the recoil exceeds a slower, 230-grain bullet? Of course we can.

Can we do it without blowing up the gun? Yes.

The wild card is this:

Can we safely drive it hard enough, and exceed the recoil impulse enough to be able to actually feel the difference? Not likely.

The felt recoil in an autopistol comes from compressing the spring and the slide's impact with the frame. It's not at all the same sort of recoil impulse felt with a fixed breech weapon, like a revolver or a bolt-action rifle. Compress the spring faster...and the recoil becomes snappier. Impact the frame harder, and the muzzle flip increases. The test would be to lock it into a Ransom Rest, and note the angle of the muzzle on firing...and then reset it without changing the tension on the friction plates, and repeat it with a different bullet.

I daresay that any difference will be too slight to make any sort of judgement call.

Force forward equals force backward.
Recoil momentum equals bullet momentum. Just no gettin' around that.

1911Tuner
August 28, 2008, 01:17 PM
We're proving that perceived recoil is based on the individual.

Not really. While perception depends on several things...including one shooter's sensitivity to recoil as compared to another's...the actual recoil...and what is absorbed by any given shooter...is subject to physics, and therefore inarguable.

If ammo lot A produces one foot pound less energy/momentum than Lot B...then Lot B produces more recoil, and the shooter feels it. Can a given shooter tell the difference? Nope.

Shooter A may report that the recoil from ammo lot B is very mild, while Shooter B swears that it "Kicks like a mule" even though the gun and ammo combination remains the same.
That's perception, and it has nothing at all to do with the actual energy and momentum.

Now, if we're to argue perception, it's a lot like the old question of beauty and the eye of the beholder...but that wasn't the OP's orginal question. At least, it wasn't worded to give that impression.

"Does a heavy bullet produce more recoil than a light one?"

The answer is:

It depends. Push a light bullet fast enough, and it'll produce a little more...assuming that we're staying within safe guidelines on pressures for the platform.

At equal velocities...the heavy bullet will be the heavy hitter, and likely will be so at equal pressures with the same powder burn rate.

jakemccoy
August 28, 2008, 01:23 PM
This thread is an example of what happens when people refuse to agree on the definition of a basic term.

1911Tuner
August 28, 2008, 01:27 PM
This thread is an example of what happens when people refuse to agree on the definition of a basic term.

Nope. It's what happens when we confuse perception with physical reality, Jake. If the barbell weighs a hundred pounds, the olympic weight lifter thinks it's light. The 97-pound weakling thinks it's heavy...but it still weighs a hundred pounds.

Vern Humphrey
August 28, 2008, 01:42 PM
If the barbell weighs a hundred pounds, the olympic weight lifter thinks it's light. The 97-pound weakling thinks it's heavy...but it still weighs a hundred pounds.a

To continue with that analogy, if we add 10 pounds to the barbell, the olympic weightlifter may still think it's light -- but he will notice that it is heavier than it was.

There is no way adding weight to the barbell will make that weightlifter think it is lighter.

1911Tuner
August 28, 2008, 01:52 PM
To continue with that analogy, if we add 10 pounds to the barbell, the olympic weightlifter may still think it's light -- but he will notice that it is heavier than it was.

There is no way adding weight to the barbell will make that weightlifter think it is lighter.

Mmmmmmaybe. An olympic lifter accustomed to a 500+ pound clean and jerk likely wouldn't notice a 10% increase on a weight that comparatively light if you added it without his knowledge. A 10% increase on a 500 pound bar...he'd notice.

jakemccoy
August 28, 2008, 03:10 PM
...and the back and forth continues because we refuse to agree on the definition of "perceived recoil."

I'm certain the original poster is not talking about the actual definition of "recoil". He's talking about "perceived recoil."

As we have proven, this discussion is literally impossible unless we define "perceived recoil" and proceed accordingly.

If you want to continue with some more meaningless keyboard masturbation, go right ahead. It's pretty funny actually.

jakemccoy
August 28, 2008, 03:32 PM
Apparently, 1911Turner already knows about techniques to reduce "perceived recoil."

http://forum.m1911.org/showthread.php?t=13060

However, for whatever reason, 1911Turner refuses to acknowledge here the difference between actual recoil and perceived recoil. Well, until we can agree on the definition of "perceived recoil", I'll just sit back here and have a good laugh at the chaos.

Phil DeGraves
August 28, 2008, 03:40 PM
Here is the original post.

The effect of a heavier weight bullet?

Is: (1) Less recoil? (2) More Recoil?


I don't see anything about "perceived" recoil. Just less or more.

What was the definition of "is'?

Vern Humphrey
August 28, 2008, 03:41 PM
However, for whatever reason, 1911Turner refuses to acknowledge here the difference between actual recoil and perceived recoil.
He knows the difference very well and has illustrated it several times in this very thread.

He also knows that perceived recoil is related to momentum -- increase the momentum of recoil significantly in a given gun, and a given shooter will perceive the increase.

He also knows that KE is not the determining factor in recoil.

jakemccoy
August 28, 2008, 03:44 PM
...and still nobody except me has provided a definition for "perceived recoil."

Well, at least I still get to enjoy the chaos.

Vern Humphrey
August 28, 2008, 03:50 PM
I don't see anything about "perceived" recoil. Just less or more.
The lad is off his lithium. Ignore him.

jakemccoy
August 28, 2008, 03:51 PM
Not really. While perception depends on several things...including one shooter's sensitivity to recoil as compared to another's...the actual recoil...and what is absorbed by any given shooter...is subject to physics, and therefore inarguable.

You start out by saying "perceived recoil" is not based on the individual. Then, you say exactly the opposite. Make up your mind, bro.

The problem is that you're so into what you're saying, you assume others don't know what they're talking about.

jakemccoy
August 28, 2008, 03:57 PM
I don't see anything about "perceived" recoil. Just less or more.


Answer this honestly... You go to a range and a new shooter is talking about "recoil". Do you think they're talking about "perceived recoil", in other words, the perception of the recoil in their hands?

(Yes.)

jakemccoy
August 28, 2008, 04:00 PM
[Vern's] mistaking actual recoil for perceived recoil.

I agree.

Headless
August 28, 2008, 04:05 PM
I've always found that lighter bullets provide less felt recoil in the few guns i've had the chance to fire multiple loadings in the same guns For example, 158gr +P remington from my model 642 kicks a lot harder than the super light 110gr all-copper corbon DPX rounds. in WWB i've always found the 180gr to be easier to control than the 165gr (both target boxes) in .40cal.

jakemccoy
August 28, 2008, 04:08 PM
I've always found that lighter bullets provide less felt recoil in the few guns i've had the chance to fire multiple loadings in the same guns...in WWB i've always found the 180gr to be easier to control than the 165gr (both target boxes) in .40cal.

You're saying the lighter bullet has less felt recoil but is harder to control.

Well, obviously, the lighter bullet has more of "something." What exactly is that something?

:banghead:

rcmodel
August 28, 2008, 05:49 PM
The problem is that you're so into what you're saying, you assume others don't know what they're talking about.Dude, you are wrong.

Please don't make it any worse then it already is.

rcmodel

jakemccoy
August 28, 2008, 05:52 PM
...still no definition

Vern Humphrey
August 28, 2008, 05:53 PM
Don't feed the troll.

jakemccoy
August 28, 2008, 05:55 PM
Vern, I went ahead and reported your posting.

The lad is off his lithium. Ignore him.
Don't feed the troll.

Sylvan-Forge
August 28, 2008, 08:33 PM
Gentlemen,

Let me tell a brief story about my subjective experience with recoil.


.40 cal. pistol, 135gr projectile, 6.0gr charge, 1180f/s.
Snap. Oww!

Same pistol, 180gr projectile, 5.5gr charge, 940f/s.
Shove. Ahh!

I know in my brain that there is a little more recoil impulse/energy in the heavier projectile, but the way it 'felt' was quite different. I 'feel' the 180 recoils less. It recoils less to me because the force is spread out differently over a period of time.
Powercurve if you will.
...

I've had various counter-intuitive experiences in different calibers and platforms..

If you can write a formula for your own subjective-perceived-felt
recoil, that is great, but you can't apply it reliably to other people.


So to make clear ..

There is measurable recoil - Fact.

There is subjective felt-recoil - Opinion.

..

Both are important to discuss, no?

.

Sylvan-Forge
August 28, 2008, 09:14 PM
Checking my records .. I'd say ~65% of my experiences have followed along with the various formulas of recoil (basically momentum p=mv).

YMMV, of course.

.

1911Tuner
August 29, 2008, 05:50 AM
.40 cal. pistol, 135gr projectile, 6.0gr charge, 1180f/s.
Snap. Oww!

Same pistol, 180gr projectile, 5.5gr charge, 940f/s.
Shove. Ahh!

Yes. If the 135 at 1180 generated more momentum than the 180 at 940, it will produce more recoil momentum, and more felt recoil.
No argument there.

With an autopistol, there is a factor that is largely ignored. I noted it once, but I'll repeat it.

The recoil impulse isn't transmitted to your hand in the same way that a revolver does it because it's on a sliding rail. If the slide were mounted on a 30-foot frame rail, without a recoil spring between them...you could fire the gun and feel nothing beyond a mild push from the rail to rail friction. You get almost nothing from the internal ballistic event...or the "explosion" of the powder charge and the resulting action/reaction between bullet and breechblock. What you feel comes from the recoil spring and the slide impacting the frame. Of the two, the slide's impact generates the more
obvious.

The recoil system is a closed system...separate and apart from the main system of the bullet, barrel, and slide. The compressing spring generates a force vector between the slide and frame. As it compresses, it pushes on both with equal force. The faster it compresses, the harder it pushes.

That "Equal and Opposite" thing works backward, too.

The impact with the frame is the one that tells the tale. If the bullet is driven hard enough and fast enough to generate more momentum than the heavier bullet...the slide will have more momentum. The slide will move faster...compressing the spring faster...and it will carry that momentum to the impact point with the frame.

Increasing the spring rate won't change anything. It will slow the slide, but will generate more forward and rearward force as it compresses than the lighter spring...so it equals out. It softens the blow at impact, but is pushing harder before that impact occurs, and you're back to square one. So, it doesn't "soften" recoil so much as it changes the amount of time that the gun recoils...and thus your perception of it. Momentum is momentum and must be conserved. All a spring rate change does is to alter the amount of time that it takes to deliver the momentum to your hand. Go and fire a Browning autoloading shotgun with its long recoil operation...and then fire a pump shotgun of the same weight. The momentum is the same. The recoil impulse is the same. Only the way that the recoil is delivered to your shoulder changes.

So, felt recoil comes from momentum...not the bullet's kinetic energy. We've used the .220 Swift/.45-70 analogy to demonstrate that. You can step it up a notch and fire an 8-pound .308 rifle with a 150-grain bullet at 2800 fps back to back with an 8-pound Sharps carbine with a 405-grain bullet at 1350 fps to demonstrate it. The .308 generates some 2600 foot-pounds of kinetic energy, and clearly beats the big, slow slug...but the .308 rifle isn't at all unpleasant...while the Sharps is decidedly so after about 8 or 10 rounds.

Anyone who is within driving distance can come and try my Sharps. BYO .308 rifle. All mine weigh less than the Sharps...but they still don't kick as hard.

1911Tuner
August 29, 2008, 07:44 AM
Vern, I went ahead and reported your posting.

Vern is a bit frustrated. Nevertheless, I shall administer discipline.

Humphrey! Drop and gimme 10. And stand up straight...and get a haircut!
You look like (expletive deleted)

Now we can all be friends again...

:)

Walkalong
August 29, 2008, 07:54 AM
Let me tell a brief story about my subjective experience with recoil.

.40 cal. pistol, 135gr projectile, 6.0gr charge, 1180f/s.
Snap. Oww!

Same pistol, 180gr projectile, 5.5gr charge, 940f/s.
Shove. Ahh!
I agree wholeheartedly. I have posted the same thing about 155 Gr vs 180Gr for a while now.

The 180 Gr at liesurely velocities is way more comfortable to shoot, to me. :)

Vern is a bit frustrated
Vern may be onto something though. There has been some pot stirring here. :scrutiny:

Vern Humphrey
August 29, 2008, 08:11 AM
One, two, three, four, five, six, seven, eight, nine, ten, Ahbone, Sagent!

MTMilitiaman
August 29, 2008, 04:17 PM
Airborne only does ten nowdays :confused:

I am sure my brother will be relieved :neener:

http://i99.photobucket.com/albums/l308/MTMilitiaman/Misc%20pics/gerberfrombro.jpg

1911Tuner
August 29, 2008, 04:58 PM
oorah

gizamo
August 29, 2008, 05:47 PM
Vern,

I'd love to take you up on the offer to shoot with you in N.C:)

I can bring a few of my Sharps with me and we can have a high old time together. Shootin' Sharps makes any day a good day!

Curious, you didn't list in your post if your shooting BP or Smokeless when you talk about 8-10 rounds becoming unpleasant to shoot. I managed to break my shoulder about a year and half ago. Fell down a flight of stairs...So nowadays I'm recoil sensitive. But I can shoot my 45/90 all afternoon and feel quite comfortable if I use Fg powder and a 550gr bullet....

So what powder are you using in that puny little 45/70 with those tiny little 405 grain pills:D:D:D

Giz

1911Tuner
August 29, 2008, 05:53 PM
'Tain't Vern that's in NC. It's moi.

For the light, plinkin' loads, I like to use 27 gains of 2400 and a cotton filler. Velocity is a lazy 1300 fps, give or take.

For punchin' holes in Abrams tanks and downin' ICBMs...43 grains of IMR 3031 for about 1700 or so.

Remember this is a Cavalry carbinen with a 22-inch barrel. It weighs 7.8 pounds empty. If the loads listed were shot in a 10.5 pound business rifle, they'd be a lot more bearable.

gizamo
August 29, 2008, 06:15 PM
Sorry about that Vern thing...LOL

Ok moi, :)

Hmmm~~~

Ever tried say 70 grs of Fg in that gun. Was what it was originally meant to shoot. Something tells me you'd report a difference in perceived recoil if you did. Might make the difference between shootin' 8-12 rounds before it became uncomfortable and shooting around 60 rounds and stopping cause you just ran out of ammo:)

Giz

1911Tuner
August 29, 2008, 06:46 PM
Giz...I've prob'ly shot enough black powder to blow up half the world. I've broken the habit. Got too lazy to clean the flippin' things.

I do, however, very much like the Sharps 50-120 stuffed fulla Goex.

But I'd go broke payin' somebody to clean it.

gizamo
August 29, 2008, 07:11 PM
Too funny,

I am starting to realize there is something really wrong with me...I actually enjoy taking the gun apart and cleaning it. Lubing it and putting it back together...then again, I enjoy casting Minnie's and big grainer bullets. Heck, I even like lubrisizing...

Think there is any help for me:)

On the flip side, I shoot the snot out of my race guns ~ generally hit them with lots of non chlorinated brake cleaner, use stainless steel brushes on them, torpedo brushes in the chambers and have even used 38 brass to clean the crud out of the cylinder flutes:eek:

I'm just a contradiction of myself foolish self!

Anywhoo, I respect your opinions and will stand by my foolish BP argument that it does effect felt recoil based on the difference in the peak pressure pulse that differs to Smokeless powders...

And anyway, wheres that Smokeless moniker come from ~ Hell, Bullseye is just as bad as some of the BP substitutes...:)

Giz

Sylvan-Forge
August 29, 2008, 10:15 PM
Yes. If the 135 at 1180 generated more momentum than the 180 at 940, it will produce more recoil momentum, and more felt recoil.
No argument there.

1911Tuner, the 180gr load made more momentum, but it felt softer .. I understand what you mean though.

Design, spring rates, slide mass and timing .. just as you have detailed :)

I believe most LE loadings are 180gr, so the pistol was probably designed for 'em.

Most (65%), but not all of my records indicate p=mv. Of the actions that are manually operated, it's about 70% that agree with momentum or momentum-based free-recoil formulas.

I guess all I can conclude is momentum formulas are correct 70% of the time for felt-recoil .. or are incorrect for 30%, if I'm feeling pessimistic :p

Larger differences in projectile weights and/or velocities will most always allow the momentum formulas to accurately predict felt-recoil in the same weapon.

.

YMMV, of course.

.

1911Tuner
August 30, 2008, 05:08 AM
1911Tuner, the 180gr load made more momentum, but it felt softer

Again...when firing an autopistol, you have to take the speed/rate of the spring compressing. A faster bullet drives the slide faster...and compresses the spring faster. The only real way to get a back-to-back comparison is to fire different rounds in a fixed breech gun because the only thing that changes is the momentum. There's no reciprocal movement and no spring to factor in. You can closely duplicate the bullet mass and velocities with a .357 revolver.

A good comparison is an old M-17 Smith .45 ACP revolver vs a 1911 pistol firing the same ammunition. The revolver's recoil will be different. A little quicker...but a little "softer" in your hand.

Limit the +P stuff in those old wheelguns, please. ;)

physics
August 30, 2008, 02:38 PM
Wow... just wow. It's funny, I always manage to avoid these threads until about this time in their life... Anyways, I AM a physicist. Mechanics isn't necessarily my forte, that being solid state and e&m, but I have taken a few years of mechanics too.

1911Tuner is dead on, he even said it better than I can. Although, my brain seems to be farting, so can you show me how a faster bullet drives/compresses the slide faster?

My only addition, is that the speed of the powder burn is important in this equation (as per the original question). A slower burning powder would give a slower recoil, and a fast burning powder would give a fast recoil.

What I mean by fast and slow is that with a fast recoil, you will feel all of the force hitting you in a small time interval, and thus will feel like more. With slow recoil, it happens over a longer period of time, so it hurts less.

Kinda like the difference between jumping off a building and landing on concrete versus landing on a stunt bag made for such activities. You slow down a whole lot faster with concrete.

I do admit though, I'm not sure how much of an effect this would have. Probably not noticeable, but possibly.

1911Tuner
August 30, 2008, 03:02 PM
Although, my brain seems to be farting, so can you show me how a faster bullet drives/compresses the slide faster?

Surely. Remember that the recoil that we feel when firing an autopistol comes from the spring and the slide impacting the frame...not from the internal ballistic event like with a fixed-breech weapon.

In order for a light bullet to have higher momentum than a heavy, slower one...it has to move faster. Momentum=Mass X Velocity.

Force forward=Force Backward.

More force must be imposed in order to drive a light bullet to a high enough velocity to top the heavy bullet's momentum. i.e If a 185-grain bullet were driven with the same powder charge as is the norm with a 230...its velocity would be a little higher, but not enough to exceed the momentum of the faster bullet.

If the light bullet were loaded to equal the momentum of the heavier one...the recoil impulse would be the same. The forces involved may be higher in order to achieve that...but my bet is that it would be undectable by the human hand. A little math and a bit of handloading will reveal much. Yep. Done it.

The slide's mass and the spring's load/resistance are constant. If more force is imposed on the slide...its rate of acceleration must be higher. The spring compresses at a faster rate, and the resulting impulse transmitted to the shooter's hand BY the spring through the frame is greater.

You can achieve the same effect by using a stronger/higher-rate spring with no other changes. Install a 14-pound recoil spring and shoot the gun. Then, slip in a 20-pound spring. You'll notice that the felt recoil is quite a bit snappier...even though the slide's momentum is the same.

1911Tuner
August 30, 2008, 03:20 PM
My only addition, is that the speed of the powder burn is important in this equation

Glad you brought that up.

In a pistol caliber...and even in a magnum revolver caliber...the bulk of the bullet's velocity and the resulting recoil impulse occurs early, during the rapid climb to peak pressure...probably within the first half-inch of bullet travel in the barrel.

Since Newton dictates that objects at rest tend to remain at rest...the more quickly you try to accelerate it, the harder it fights that acceleration.

Lift a 50-pound weight at a rate of 1 foot per minute...then lift it at a rate of 10 feet per second.

The frictional resistance on the bullet as it enters the rifling also works to resist...so the rise to peak pressure...and peak force...are early and fast.

What little additional bullet acceleration that comes after the peak, and during the rapid drop of pressure and force...means almost nothing, recoil-wise.

Think about it like this.

If the rule of thumb of 35 fps per inch of barrel gained or lost is accurate...and it's pretty close...

If we get 850 fps from a 5-inch barrel...and we get 35fps per inch X five...then we're getting 175 fps in the barrel. Where does the other 675 feet per second come from?

Let's get it a little closer.

If the greatest percentage of the bullet's final velocity occurs in the first half-inch...we're down to 4.5 inches X 35. That's 137 fps...leaving
713 fps unaccounted for.

Even slow rifle powders peak rapidly...probably within the first 2-3 inches of bullet travel even with the really slow powders.

So...with normal pistol powders that are suitable for a given application...is there enough difference in the burn rate between Bullseye and Unique to detect a difference? Not likely. Possibly between Unique and Olin 296 or H-110...but my opinion is that it would take a sensitive hand if both cartridges were loaded to equal pressures.

Zedo
August 30, 2008, 03:27 PM
"Subjective recoil" -- a great deal depends on the fit of the gun. Drop of the comb, length of pull in the stock, balance of the firearm. All these will affect "perceived recoil."

The experience of the shooter with heavily recoiling firearms has a significant bearing on "perceived recoil." And on that note, here's a link to some yahoos shooting a 577 T Rex.

www.youtube.com/watch?v=-EVqT3XEzss

www.youtube.com/watch?v=CQJSZs-euZU

What you'll see in these clips is inexperienced shooters being tossed across the room from the recoil of this gun/load. The last shooter in one of these clips has experience shooting a gun of this caliber, and so is able to manage the recoil.

I have a .458 Win. Mag. -- 500 gr. bullet at 2161 fps. The calculated recoil is in the realm of 65 ft. lbs. in a 9 lb. gun. Nominal recoil for 30-06 is in the realm of 20 ft. lbs. 45-70 Govt. runs about 40 ft. lbs. recoil w/ 350 gr. bullet.

But because the gun fits, and is designed to shoot this caliber (Ruger No. 1 Tropical), the recoil, while significant, is not what I'd call "uncomfortable" --

But your mileage may vary.

http://i272.photobucket.com/albums/jj188/Ontologix/458-bullet.jpg

http://i272.photobucket.com/albums/jj188/Ontologix/Ruger458.jpg

Sylvan-Forge
August 31, 2008, 04:05 PM
Again...when firing an autopistol, you have to take the speed/rate of the spring compressing. A faster bullet drives the slide faster...and compresses the spring faster.

I have and I'm still not getting it :o

The 180gr @ 940 f/s using 5.5gr charge shows greater recoil impulse, firearm velocity and free recoil energy than the 135gr @ 1180 using 6.0gr charge ...

Here's the written formula I used:
http://www.loadammo.com/Topics/August01.htm

Yields the same as the calculator that rcmodel linked:
http://www.handloads.com/calc/recoil.asp


.

Only way I can fathom it feeling less is that it takes the 180gr bullet a longer time to leave the barrel than the 135gr even though the slide (after unlocking) is being driven back with more oomph.

.

1911Tuner
August 31, 2008, 07:12 PM
I dunno quite how to explain it.
First, the calculation of bullet/recoil momentum is far too complex. The IDPA/USPSA's "Power factor" is no more than a measure of momentum...or how far the bullet will move a ballistic pendulum. Grain weight times velocity divided by 1,000 is the formula. Using this, the venerable .45 hardball load of 230/800 fps gives us a power factor of 184, and the same bullet at 750 fps just squeakes over the line with 172.

Using the same calculation, your 135/1180 churns up a power factor of 159. It doesn't make major, but it doesn't miss by much. The 180/940 does a little better at 169...barely missing major.

So, we have a little more momentum with the slower, heavier bullet...but not enough to feel any real difference on the other end of the gun. At least, not in my hand. Doing a side-by-side comparison of my 200 grain SWCs at 800 fps with my 230s at 800...I can tell a little difference if I'm really paying attention...but nothing like being reported in the .40 caliber 135/180 comparison.

So, there's obviously something else going on. That something is the slide's reciprocation and changing center of gravity. The speed of the recoil spring's compression, and the slide's impact with the frame.

Many people mistakenly believe that the recoil that the feel when firing an autopistol is the result of the actual action/reaction event between the bullet and the breechblock. It's not. What generates the felt recoil is the action/reaction event between the slide and the frame via the spring and the slide's suddent stop against the frame...and then we feel yet another one as the spring accelerates the slide back to battery. All that violent slam-bangin' around fools our mind into thinking" "Wow! This thing really kicks! It must be some kinda pow'rful!"

If you can arrange to shoot the same two rounds in a revolver, your brain won't be quite as impressed because it's all over with in one quick punch.

Then there's the matter of the mass of the powder charge. The 135/1180 uses a heavier charge...adding to the total mass of the ejectiva. That adds to the recoil momentum and energy by the weight of the powder charge in grains. There's also the matter of the pressures. Most often, the lightweight scrreamers are loaded to higher pressures. +P if you like. That accelerates the powder gasses...adding to the effect.

Incidentally, the heavier bullet's dwell time in the barrel has almost nothing to do with felt recoil in a pistol...and little more in a revolver. A rifle wth a 22-inch barrel...sure. The short recoil system of the 1911 and probably also the Glock, etal...only gets a recoil impetus during the first 1/10th inch or so of slide travel. At that point, the bullet is gone, and can't generate any more "push" through the force vector...and the slide continues on via the momentum conserved during that time. The few milliseconds' difference in dwell time between the two bullets is pretty much meaningless.

What is a real factor is the speed at which the slide compresses the spring. Newton's 1st law of inertia mandates that it takes more force to get an object moving than it takes to keep it moving, or even accelerate it to a higher velocity. We've seen that the greatest percentage of the bullet's final velocity occurs within the first half-inch of bullet travel. With really fast powders, it may even be less. Factoring in the bullet's inertial mass, it takes more force to accelerate the 135 grain bullet to some 970 fps...of the total of 1180...than it takes to accelerate the 180 to 730 fps, with the total being 940. The 135 grain bullet's velocity at a half-inch of travel is faster than the 180s is at the muzzle. Think about that.

Force forward equals force backward. This is Newton's 3rd law simplified. Whatever force drives the bullet is also visited on the slide. Simple physics determines that when a greater force is applied, an object of a given mass will accelerate faster than the same object with a lesser force applied. Witness that a peak pressure of 25,000 psi will produce higher velocities with a given bullet than will 20,000. Simple physics.

So...while the slide's momentum must be ewqual to that of the bullet...in an autopistol, or any spring-assisted action...it doesn't tell the whole tale as far as felt recoil is concerned. Go and find a Smith 10MM revolver and shoot the ammo through it. Wear plugs and muffs to negate the sensory effect of the muzzle blast. I think you'll see that the 135/1180 load isn't quite as rambunctious as you think it is. If you have a good hand, you may even be able to tell the difference between it and the 180/940 load.

Vern Humphrey
August 31, 2008, 07:29 PM
One interesting experiment is to shoot the Colt Service Ace or Service Ace Conversion Kit. The floating chamber is actually noticeable, and you can feel if if you're paying attention. There is a double bump effect, first as the floating chamber hits the slide, then as the slide hits the frame.

1911Tuner
August 31, 2008, 07:38 PM
One interesting experiment is to shoot the Colt Service Ace or Service Ace Conversion Kit.

Excellent example of what I'm talkin' about!

*smack*

Why didn't I think of that?

:rolleyes:

DaveBeal
August 31, 2008, 07:52 PM
Here's one way to think of it: Recoil is caused by the pressure of the propellent gas on the bolt of the gun. All other things being equal, a heavier bullet accelerates more slowly and so takes longer to emerge from the barrel, giving the gas more time to push backward on the gun. So a heavier bullet should cause more recoil.

Sylvan-Forge
August 31, 2008, 08:08 PM
Tuner, ya gone and done melted my brain! :p

Thank you for all the explaining .. I'll try and go through it tommorrow after some sleep.

One thing is for sure, this thread has surely shown that

(3) There's more to it.

.

Best!

.

1911Tuner
August 31, 2008, 08:36 PM
Dave...Kinda-sorta, but again...the dwell time difference is so small that we couldn't detect it. It doesn't apply the same way in a self-shicker as it does in a fixed breech gun anyway. With an autpistol...if there was no spring between the slide and frame, the "gun" will recoil while the frame stands still...until it hits the impact abutment, at least. If the frame rails were 30 feet long, you could fire it and feel almost nothing in the way of recoil. The recoil is all in the slide...which transfers its momentum through the recoil spring to the frame, and ultimately...your hand. The slide hitting the impact abutment then generates the second impulse that causes the greatest percentage of muzzle flip.
Then, the spring accelerates the slide forward...giving us another impulse as it imposes equal /opposite force against the frame.

It's known as sensory overload because it's all coming so fast that our brain can't separate the three different impulses, nor tell the difference.

With a fixed breech weapon...it's all over in one quick punch. We feel the result of the actual ballistic event...the action/reaction between bullet and bolt.

Incidentally...all the things that are acting on the slide are known as "Outside Forces." Momentum will be conserved forever in the absence of outside force. A bullet fired in the vacuum of outer space will continue at the muzzle velocity forever unless and until it either hits something or comes under the influence of a gravitational field. Anything that has the opportunity to influence a moving object will do just that.

In firing a rifle, the action/reaction event involves the bullet, bolt, and force vector provided by the expanding gas. Everything else constitutes outside force. The rifle barrel drags on the bullet. The receiver adds to the rifle's mass. The stock...the scope...and finally...the shooter. All these things are outside forces that oppose the objects in motion and work to bring them back to a stop...to restore equilibrium...the state of no motion, where compelling and resistive forces are balanced.

So, yes Sylvan. There's more to it. A lot more.

Elm Creek Smith
September 1, 2008, 01:35 AM
All other things being equal, the heavier bullet results in more recoil.

Oh, yeah: Light bullets shoot low.

ECS

Sylvan-Forge
September 1, 2008, 04:21 AM
It's known as sensory overload because it's all coming so fast that our brain can't separate the three different impulses, nor tell the difference.

I think this is where we deviate.
The 180@940 event takes longer to complete than the 135@1180.

All other things being equal, the heavier bullet results in more recoil.

Yes, but not neccessarily more perceived recoil.

.

Both events plotted out:
180@940 has more recoil energy, but longer period.
135@1180 has less recoil energy, but shorter period.

.

IIRC, unlocking won't fully occur until the case lets go of the chamber walls after the bullet leaves the muzzle.
Maybe this hitch is what changes things just enough to improve felt recoil (for me anyways).

.

Sylvan-Forge
September 1, 2008, 04:49 AM
In my log books, I've 10 of 31 results detailing the same deal - 9 revolvers and 1 bolt action with heavier projectiles giving higher recoil energies but somehow softer felt recoil than lighter/faster comparison loads.

It's got to be the time factor.

.

Or maybe I'm just crazy :uhoh:

.

1911Tuner
September 1, 2008, 05:58 AM
The 180@940 event takes longer to complete than the 135@1180.

But how much longer...and can you perceive the difference in time that's measured in just a few milliseconds? You still don't seem to be grasping that you don't feel recoil in an auto from the ballistic event. You feel the slide compressing the spring and the impact with the frame...and by the time that you actually start to feel it, the bullet is gone.

In my log books, I've 10 of 31 results detailing the same deal - 9 revolvers and 1 bolt action with heavier projectiles giving higher recoil energies but somehow softer felt recoil than lighter/faster comparison loads

Yeah. Those are fixed-breech guns. The perception of recoil is different than a self-shucker. All you have is the recoil impetus. With autoloaders, you've got all that slam-bang action and a moving slide.

An example is an old 1937 Brazillian contract Smith & Wesson revolver in .45 ACP that my step-father now owns. When I had it...about 20 years ago...a friend was with me at the range, and we shot it a little along with my 1911s. He asked why it "Kicked less" with the same ammunition. I didn't have a good, plausible answer for him, and that's what got me really studyin' on it. If you can find a Smith and Wesson 10MM revolver, and fire the two .40 loads back to back...you'll also notice that they both feel diferent than when they're shot in an autopistol.

1911Tuner
September 1, 2008, 06:34 AM
A little long...so read carefully.

Let's try this again with a brief description of how a short recoil pistol works. Since I'm most familiar with the 1911, I'll use it. There's very little difference anyway.

Bang! The bullet starts its trip through the barrel. Assuming zero headspace, the slide starts rearward at the same instant. The slide pulls the barrel backward with it via the upper barrel lugs.

At 1/10th inch of slide travel, the barrel reaches the beginning of the linkdown point...and the bullet exits...and the barrel starts to link down. The bullet MUST be gone at that point, because if the breech opens before the pressure drops, the case will burst. Once the bullet is gone, it has no more influence.

1/10th inch of slide travel means that the spring has compressed 1/10th inch further than its static preload. The static spring preload in a 5-inch pistol with a 16 pound spring is about 8.5-9 pounds. Add a tenth inch of extra compression to that preload...and that's what you feel pushing against the frame. Go to the chart and find the gun/ammo combination that gives 9 pounds of free recoil...and you can tell how much recoil that pistol is providing at the point of bullet exit. Once the bullet has left the barrel, the action side of the primary action/reaction event is gone, and is no longer part of the equation. From that point, all recoil that you feel is up to the slide and the spring.

Now, the slide is compressing the spring. The spring becomes a force vector in a separate closed system. That force vector is between the slide and the frame. As the spring compresses, it fights to push the slide forward. As it pushes the slide in one direction, it pushes the frame in the opposite direction with equal force. Just prior to the point of slide to frame impact...you're feeling 16 pounds of free recoil.

Wham! The slide hits the frame at speed, and torques the gun upward in what we call "Muzzle Flip" Before that impact, the muzzle has "flipped" very little. Slow-motion videos will bear this out...and they will also show that at the instant of bullet exit, the gun has barely moved.

45auto
September 1, 2008, 08:06 AM
Using the 1911 as an example, IPSIC/IDPA as the sport, many people feel the heavier 230 grain at a lower velocity compared to the 200 grain at higher velocity, feels "softer" to shoot. Both at the same power factor.

I'm not saying I can feel it, or everyone can, but it seems many can. That could be the slide speed, different "feel", muzzle coming back to point, etc.

I have no point to make on this, ;), simply observing. Of course, changing recoil spring weights, mainspring combo's etc can/do "affect" how you want your "recoil" sensation.

1911Tuner
September 1, 2008, 08:20 AM
Found what I was lookin' for! Play this on High Res, and pay particular attention to the pistol that stars in two clips back to back. In one, it's tethered by a spring. In the other, it's not.

Then watch the last 1911 just before the revolver. It's an excellent stop-action sequence that reveals many things. First will be a light gas blow-by...followed by the bullet nose peekin' out...followed by the blast of gas after the bullet exit. The slide is moving the whole time, but take note of how little it's moved at the point of bullet exit.

Most interesting is the bolt bounce in the AR15 sequence.

Watch and learn...

http://www.trippresearch.com/media/movement/hispeedgateway.html

Vern Humphrey
September 1, 2008, 08:44 AM
Or just look at a fired case -- clearly, the gun is still locked before the bullet exits the muzzle (if it were not, the case wouldn't be in any shape to be reloaded!) Then note how much rearward motion of the slide is needed to unlock the gun.

Sylvan-Forge
September 1, 2008, 09:31 AM
1911Tuner .. I've learned a lot of this stuff from you and your references and do appreciate your helpfulness. Please don't take any of this the wrong way .. Not trying to win, I'm trying to understand .. there has to be some kind of explaination for my and others counter-intuitive felt-recoil experiences from these loads.

But how much longer...and can you perceive the difference in time that's measured in just a few milliseconds?
I honestly don't know, perhaps it is the differing magnitudes of force delivered over time that counts .. did some unscientific doodling and came up with this:
http://www.thehighroad.org/attachment.php?attachmentid=83995&d=1220274791
Mirror plot. 180 top, 135 bottom.

You feel the slide compressing the spring <snip>
Around 16lbs. you say, prior to abutement..

..and then impact with the frame...
Abrupt stop! The red lines in the doodle graph.

If it takes longer to get the bullet out of the muzzle, it should take longer for the slide to hit the abutement due to the counteracting (slowing) forces of the barrel being pushed forward by the bullet, the case remaining obturated due to pressure in the bore still sealed by the bullet and possibly spring dynamics .. effectively delaying things fractionally (perhaps enough) at the link-down point. Over doing it of course would let the extractor slip out of the groove, rip the case head off or rupture the case.

?

.

Thanks for the vid link .. I'm on dial-up, so which one to get?
Can't see extreme left of page either ..

.

Vern Humphrey
September 1, 2008, 09:46 AM
If it takes longer to get the bullet out of the muzzle, it should take longer for the slide to hit the abutement due to the counteracting (slowing) forces of the barrel being pushed forward by the bullet
Not necessarily.

The motion of the slide is governed by the momentum of the ejecta, not the dwell time.

Consider the formula: M1 X V1 = M2 X V2.

The mass of the slide (M2) is the fixed component in this equation. It isn't changed by ejecta mass or velocity. So if you change ejecta mass or velocity, you automatically change slide velocity.

If a given round has more momentum, the slide will come back faster -- even if that bullet has less velocity than a lighter bullet.

Sylvan-Forge
September 1, 2008, 09:53 AM
Ahh ok, that makes sense Mr. Humphrey .. equal and opposite ..

Doh!

Do you agree on "case" obturation slowing it a bit at link-down?

.

Edit: sorry, forgot to specify 'case' obturation

Vern Humphrey
September 1, 2008, 10:06 AM
Do you agree on obturation slowing it a bit at link-down?

Friction or rifling resistance may have an effect -- rifling can raise pressures and retard velocity somewhat. But any difference between different weight bullets in the same barrel would be very small.

Sylvan-Forge
September 1, 2008, 10:08 AM
Light and dark gray lines in doodle graph showing theorized slowing due to case obturation (and possibly spring dynamics?)

http://www.thehighroad.org/attachment.php?attachmentid=83996&d=1220278013

.

BruceRDucer
September 1, 2008, 10:10 AM
/

Sylvan Forge, in your original post, you showed the calculation for a pistol bullet, and indicated:

3.7409 ft-lbs of recoil

So roughly speaking (and a guestimate is as good enough for me) does that mean if a rifle fired the same, the impact on the shoulder would be 3.7 POUNDS?

Does ft-lbs equate to pounds of impact force exactly, or is the shoulder dimension part of the calculation?

If a 30-06 rifle fires a 150 versus a 180 grain bullet, what might the difference in recoil impact be on the shoulder?

(also, this would be using standard, off the shelf factory loads....nothing exotic, custom or fancy)

/:uhoh::uhoh::uhoh::uhoh::uhoh::uhoh:

Sylvan-Forge
September 1, 2008, 10:11 AM
I meant case obturation, not bullet .. sorry bout that.

Vern Humphrey
September 1, 2008, 10:15 AM
Case obturation depends on internal case pressure. When the bullet exits the bore, the internal pressure drops dramatically. In a properly timed gun, unlocking occurs as the bullet exits. There are exceptions to this -- blowback and delayed blowback weapons are examples.

So in a locked breech weapon, with proper timing, case obturation should have little effect.

Sylvan-Forge
September 1, 2008, 10:28 AM
BruceRDucer,

Yes it would be 3.7lbs delivered to the shoulder assuming muzzle vel and rifle weight are the same as factored for the pistol.

Here's the calculator:
http://www.handloads.com/calc/recoil.asp

.

My pitch is that with heavier bullets the powercurve is shaped differently and drawn out over a longer period of time giving some folks the sense that it recoils less even if the formulas say more.

.

YMMV!

.

1911Tuner
September 1, 2008, 10:36 AM
I understand, Sylvan...but you still haven't wrapped your head around the fact that...while the 180 may indeed have more momentum at exit velocity...it may not necessarily be the case at the beginning of the event, where the majority of recoil occurs. Muzzle velocity has very little to do with what you feel as recoil, and...in an autopistol...you feel nothing from the actual internal ballistic event. By the time you feel it, the action and reaction between the bullet and the breechblock is over. Done. Finito.

What you feel comes from the slide compressing the spring and its impact with the frame. If you've watched the videos, you've seen it.

In order for the slide to impact the frame harder, it must have more momentum. In order for it to have more momentum, it must be moving faster at impact. Must be. Momentum is a function of mass and velocity.

In order for it to have more velocity at impact, it must have started out faster...during the peak pressure and force imposed on it. That occurs at about a half-inch of bullet travel, or less...just as the bullet hits the rifling.

It's at that point in the sequence that peak force is imposed, and it's at that point that about 95% of the recoil impulse is generated...and you don't even feel it yet. The slide and bullet do...but all you get is a little push from the spring...and it's at that point that the speedy 135's momentum is greater...even though it may not be at exit.

Then note how much rearward motion of the slide is needed to unlock the gun.

Thank you, Vern!

Unlock begins at about 1/10th inch of slide travel. The bullet must be gone, or at the point of leaving before that can happen. By 1/8th inch, the breech is open, and even the residual gasses are gone, and can't impose any more thrust on the slide. The slide can't accelerate any faster after that happens any more than a bullet can accelerate after it leaves the muzzle.

Sylvan...Read that again. Once the bullet exits the muzzle, there is no more recoil. The action/reaction event is over. The bullet and the slide are moving because of the momentum that they conserved during the event.

Now, back to the bullet for a minute.

The bullet is resisted by the frictional forces imposed by the barrel. An object of lesser mass loses momentum at a faster rate than one of greater mass...so the 135 bullet loses momentum at a faster rate. The frictional resistance is constant.

Now for the slide and spring.

The slide's mass is constant. The spring's rate is constant. The slide's loss of momentum is controlled by the spring.

In firing the 135/1180 load, the slide is moving faster at the moment of peak force...pressure. It has to be in order to match the bullet's momentum.

Now for an analogy that may help.

Fire a .30 caliber bullet at 3,000 fps muzzle velocity and a 180 grain bullet at 2800 fps MV. At 100 yards, the lighter, faster bullet has lost a greater percentage of its initial velocity than the heavier one. By 300 yards, the 180's speed is roughly equal to the 150's. By 400 yards, they're neck and neck...the 180 is closing the gap. At 500 yards, the 180 overtakes the 150 and passes it.
It's actually moving faster, even though it started slower.

Why?

Two reasons. Momentum is the obvious answer...even if they started out at equal momentum. The faster the bullet is moving when it hits the air, the harder the air fights it...offering it greater resistance than on the slower bullet...even though the atmospheric pressure is identical.
The faster any object is moving when it encounters an outside force, the faster that force will slow it down.

So, forget momentum calculations at muzzle velocity, and consider what happens while the bullet and breechblock are compelled by peak pressure and force.

To recap:

In order for a given load to produce more felt recoil than another one in an autopistol, the slide must hit the frame with more momentum. Because momentum is a function of mass and velocity, it must be moving faster. If it's moving faster, it's compressing the spring faster. When the spring compresses faster, it pushes backward on the frame faster.

Sylvan-Forge
September 1, 2008, 10:56 AM
1911Tuner, thanks! I'm pretty sure I've got the mechanics down, mostly.

And I think I might now understand what I have been experiencing:.

The powercurve leading up to that point was broader and smoother or whatever, giving the sensation that things are not abrupt as they seem to be with the lighter faster load.
More prepped or 'momentumized' leading up to the finale :) rather than a such a recurved/rapid rise to finale.
.

Sound good? :D
If not, that's cool .. my eggs are fried.
Good exersize though! Thanks for it!

.

1911Tuner
September 1, 2008, 11:29 AM
I dunno. Sounds a bit too complicated...

"Power Curve" suggests that the actual recoil impulse occurs over a longer period of time..which even though it probably does...wouldn't make any practical difference with the powder burn rates in an autopistol cartridge. Studying the pressure charts with quick powders shows a rapid peak instead of a slow climb, with very little area under the "curve" Once it peaks, it drops about as fast as it took to get there.

Anyway...

It seems like you've seen that what you feel as recoil doesn't come from the ballistic event...in an autopistol.
The greatest percentage of the felt recoil...the gun's movement...comes from the slide impacting the frame.

If the bullet is gone at 1/10th to 1/8th inch of slide travel, by the time the slide hits the frame...the bullet has already hit a 25-yard target and likely come to a stop in the berm.

Because recoil is the reaction side of an action/reaction event...once the action side of the equation is missing...the reaction is over. IOW, by the time the slide hits the frame, and you feel the effects, there is no more recoil because the bullet isn't there. Recoil occurs while the bullet is in the barrel and being driven forward. No bullet/no force/no recoil.

BruceRDucer
September 1, 2008, 06:48 PM
I have a box of Remington Express Bronze Point in 30-06 Springfield 180 grain

Is there an online chart that will show:

(1) Powder Charge in Grains

(2) Velocity in fps

My rifle's weight is 6 3/4 lbs

I would like to use your calculator or formula to obtain the recoil data. Thanks.

/

Sylvan-Forge
September 2, 2008, 08:02 AM
BruceRDucer,

Finding the exact powder charge might prove a little difficult as the manufacturers usually won't release that. You could try asking around in the handloading forum.

The most accurate way to obtain velocity figures is using a chronograph.

Here's Remington Ballistics for the Express Bronze Point:
http://www.remington.com/products/ammunition/ballistics/comparative_ballistics_results.aspx?data=R30066

Looks like they are using a 24" barrel and getting 2700 f/s @ muzzle.

In the Lyman 48th Reloading handbook, looks like a good average powder charge is about 55 grains for a 180 gr. bullet.

.

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