Recoil question


PDA






falldowngoboom
July 10, 2009, 06:33 PM
Had a quick question about recoil... Aside from variations in a particular gun (weight, configuration, etc.) is recoil purely a function of a cartridge's ft-lbs. at the muzzle? Seems like it is, but was wondering if there were other factors I'm not aware of.

P.S. Any tips to get acclimated to '06 recoil other than practice, practice, practice, would be welcomed! :what:

If you enjoyed reading about "Recoil question" here in TheHighRoad.org archive, you'll LOVE our community. Come join TheHighRoad.org today for the full version!
Kingcreek
July 10, 2009, 06:37 PM
goboomfalldown, its just physics. ie the size and stance of the shooter, design of the stock, weight of the firearm, etc. are all factors.

SaMx
July 10, 2009, 06:37 PM
The recoil force is a function of momentum.

But you can reduce the felt recoil by either adding weight to the gun, and making sure you have proper form. Make sure the stock is tucked into your shoulder tightly, ideally you should rock back with the gun, rather than having the stock slam into your shoulder.

rcmodel
July 10, 2009, 06:48 PM
Recoil is generated by the "ejecta" of the load.
That includes the bullet, powder and gases.

Energy is an indicator, but other factors are a work as well.
You could have a very light 22-250 bullet moving at very high velocity that would give a muzzle energy figure almost identical to a 240 grain .44 Magnum.
But recoil would be nowhere near as much as the .44 Magnum 240 grain bullet going half as fast.

Here is a simple recoil calculator to play with.
http://www.handloads.com/calc/recoil.asp

Remington Reduced Recoil 30-06 loads might help you get over the hump.
http://www.remington.com/products/ammunition/centerfire/managed-Recoil.asp

rc

cbrgator
July 10, 2009, 06:52 PM
It is a function of the the cartridge's ft/lbs, design of the gun, and the weight of the gun.

Uncle Mike
July 10, 2009, 06:53 PM
Newton's 3rd. law of relativity... for every reaction there is an equal and opposite reaction.

Whenever a particle A exerts a force on another particle B, B simultaneously exerts a force on A with the same magnitude in the opposite direction. The strong form of the law further postulates that these two forces act along the same line. This law is often simplified into the sentence,

"To every action there is an equal and opposite reaction."

So... this pees on the movies shot of the 45acp round impacting the bad guy, and the bad guy being blown backwards several yards, if it were true this way, the shooter would be blown back with the same force... all things being equal.

:D

SaMx
July 10, 2009, 07:01 PM
actually the shooter wouldn't necessarily feel the same force
I said the recoil force is a function of the momentum, it's actually a function of the change in momentum over time. If the bullet stopped more suddenly in the target than it took to accelerate it in the barrel of the gun, the target would feel a larger force. You can think of it as a small force over a longer period of time being the same as a large force over a short period of time.

It doesn't matter anyway, because it's never the case that a bullet slows down in the target faster than it speeds up in the gun.

SaMx
July 10, 2009, 07:02 PM
oops, double tap

anyway, the force isn't just based on the change in momentum over time, it can also be found from the change in kinetic energy over distance. So assuming the guy is getting shot with a 5" barrelled 1911, for him to feel more force than the recoil of the pistol, he bullet would have to penetrate less than 5 inches.

rcmodel
July 10, 2009, 07:04 PM
Actually it is the case, when you shoot a steel target.

The bullet stops instantly, much faster then it accelerated out of the gun.

But the steel plate isn't blown back 20 yards either!

Most of the bullets energy was converted to heat & deforming/distroying the bullet when it struck the steel plate.

rc

Acera
July 10, 2009, 07:12 PM
Take a look at this table, it puts a lot of the above stuff into perspective.

http://www.chuckhawks.com/recoil_table.htm

Uncle Mike
July 10, 2009, 07:13 PM
actually the shooter wouldn't necessarily feel the same force

Momentum = The physical quantity of mass, moving at a given velocity.

in essence... (Mass X velocity) = Momentum

The shooter does have the SAME forces applied to him/her as does the bullet upon the bullets acceleration from being at rest to peak gain(velocity).

Whether the shooter FEELS this is quantitative to external properties such as weight, stock design, clothing, et cetera.

:D

falldowngoboom
July 10, 2009, 07:22 PM
Recoil is generated by the "ejecta" of the load.
That includes the bullet, powder and gases.

Energy is an indicator, but other factors are a work as well.
You could have a very light 22-250 bullet moving at very high velocity that would give a muzzle energy figure almost identical to a 240 grain .44 Magnum.
But recoil would be nowhere near as much as the .44 Magnum 240 grain bullet going half as fast.

Here is a simple recoil calculator to play with.
http://www.handloads.com/calc/recoil.asp

Remington Reduced Recoil 30-06 loads might help you get over the hump.
http://www.remington.com/products/ammunition/centerfire/managed-Recoil.asp

rc

Thanks for the responses guys. RC, if that recoil calculator is correct (I believe it is), it seems you're right about ft-lbs. not being a good indicator (at all!) of recoil. SaMx, I guess I just figured ft-lbs. was a measure of momentum, but it's not. For example, a 150g bullet at 3000fps has about the same ft-lbs. (2997) as a 216g bullet at 2500fps, but the momentum is 64 and 77, respectively. I guess I don't really understand ft-lbs. and why it's not a 1:1 relation with momentum. I get that it's an energy figure, but seems to me like that could translate directly to momentum. Anyway, this begs the question why not give ballistics data in terms of momentum instead of ft-lbs.? Seems to me momentum is what hunters are really thinking about when they read ft-lbs. I know I was.

schlockinz
July 10, 2009, 07:24 PM
There are different types of recoil as well (big push versus very sharp recoil).

But, its mainly an impulse deal, eating more bacon and drinking beer will help with recoil ;)

falldowngoboom
July 10, 2009, 07:25 PM
Momentum = The physical quantity of mass, moving at a given velocity.

in essence... (Mass X velocity) = Momentum

The shooter does have the SAME forces applied to him/her as does the bullet upon the bullets acceleration from being at rest to peak gain(velocity).

Whether the shooter FEELS this is quantitative to external properties such as weight, stock design, clothing, et cetera.

:D

I believe you guys are talking about two different things. SaMX, I think you're talking about force felt by the shooter vs. target, and Uncle Mike, I think you're talking about force on shooter vs. bullet. Really, you guys are both right, LOL. :D

rcmodel
July 10, 2009, 07:26 PM
Anyway, this begs the question why not give ballistics data in terms of momentum instead of ft-lbs.?
Well, heres another calculator to play with.
http://www.handloads.com/calc/quick.asp

People have been arguing about Momentum, Knock-down, Knock out, Muzzle energy, and a whole bunch of other things for many many years as it related to killing power.

I agree energy is a fairly meaningless figure, and anyone else would too if they had shot a few head of game with an old 45-70 or shotgun slug.

rc

schlockinz
July 10, 2009, 07:27 PM
momentum is mass x velocity = p

Kinetic energy is mass x velocity x velocity x .5

force is just mass x acceleration, or dp/dt

Thats why its more closely related to momentum

falldowngoboom
July 10, 2009, 07:27 PM
There are different types of recoil as well (big push versus very sharp recoil).

But, its mainly an impulse deal, eating more bacon and drinking beer will help with recoil ;)

Certainly the best advice yet on reducing felt recoil. Been looking for an excuse to let myself go. Will get on that right away!

SaMx
July 10, 2009, 07:31 PM
I believe you guys are talking about two different things. SaMX, I think you're talking about force felt by the shooter vs. target, and Uncle Mike, I think you're talking about force on shooter vs. bullet. Really, you guys are both right, LOL.

yup, I was about to say that.

ballistics is a really cool subject, because on the surface it's so simple, but when you start looking at it in detail there's a whole lot of things going on, and a whole lot of ways to describe them. It's even more complicated when you look at terminal ballistics.

Shadow 7D
July 10, 2009, 07:46 PM
On the practical side, a muzzle device can help deflect some of the backward force, some can even change it to forward force, a shoulder pad can help, and lets not forget stock ergonomics. The gas acts the same way a rocket engine does, making the recoil I believe greater than the bullet ft/lb because you have to calculate in the mass / force of the gas.

Uncle Mike
July 10, 2009, 07:50 PM
ballistics is a really cool subject, because on the surface it's so simple, but when you start looking at it in detail there's a whole lot of things going on, and a whole lot of ways to describe them. It's even more complicated when you look at terminal ballistics.

Allz I nose is mys 30-06 kicks harder than mys 243!:D
But deer die just as fast with the 243 as they do with the 30-06, now the 30-06 kicks harder so it should kill dem deer better huh?

Believe it or not... I actually have heard customers say this very thing.:banghead:

:D

schlockinz
July 10, 2009, 08:24 PM
Fastest i've ever dropped a deer was with a .22LR pistol, so maybe the less recoil it has the more stopping power it has :confused:



Before I get jumped on for this, the deer was head shot after I wounded it (flinched while I was still getting used to a gun that kicked), so we dispatched it with the pistol since it could still run, but let us within 15ft of herself.

AK103K
July 10, 2009, 08:40 PM
Not to get too technical, but I'd say it was the result of pulling the trigger. :)

P.S. Any tips to get acclimated to '06 recoil other than practice, practice, practice, would be welcomed!
Learn to shoot from field positions. Pull the rifle snugly into the "pocket" of your shoulder and get a good cheek weld on the stock, with your thumb off to and along the side of the stock, not across the top. You want to rock with the rifle, not get punched by it.

gunnie
July 11, 2009, 01:04 AM
then there are the constipations of precieved recoil VS actual recoil.....

a gas operated semiautomatic will spread the recoil over a longer period, making it seem less.

as mentioned above, a muzzle break keeps the residual gas pressure from increasing the percieved recoil. current testing has shown that the gas looses so much velocity when vented/redirected backward as to be of little effect.

a mercury supressor in the stock will decrease the percieved recoil. as will a sorbathane recoil pad, as mentioned above.

a buttstock with little drop will make the rifle push straight back. some feel this helps reduce percieved recoil by limiting "muzzle flip".

the KRISS carbine has a counter weight that moves against the recoil in an opposite direction when fired, reducing percieved recoil.

$0.02

gunnie

falldowngoboom
July 11, 2009, 02:22 PM
Now that I think about it, I think it's more the concussion that I need to get used to rather than the physical kick. I get shell-shock for just a split second, and I'm sure that makes me anticipation of the shot. Hair trigger helps though, cause I never have time to--BOOM!. See what I mean? :D

Thanks for the comments guys. I doubt I'll be installing anything on the rifle but will think about a recoil pad.

dagger dog
July 11, 2009, 08:32 PM
The '06 is on the cusp for perceived recoil for the majority of shooters. In the heavier bullet loadings 180 grs and up, in a lightweight gun 7 pounds or so, with an American style stock, ( recoil on a stock with more drop at the heel will feel heavier, autos recoil less) this caliber is just about the stopping point for being comfortable to most shooters.

A lot of perceived recoil is relative to the shooter, shots taken at paper targets are perceived to recoil more than a shot taken in the heat of the chase of game. The handling of recoil on any rifle is subject to the experiance of the shooter.

Shadow 7D
July 12, 2009, 04:46 AM
For anyone doubting a "muzzle device" go stand next to a Barret

1858
July 12, 2009, 06:55 PM
Newton's 3rd. law of relativity motion ... for every reaction there is an equal and opposite reaction.

:D

You could have a very light 22-250 bullet moving at very high velocity that would give a muzzle energy figure almost identical to a 240 grain .44 Magnum. But recoil would be nowhere near as much as the .44 Magnum 240 grain bullet going half as fast.

If you think about it, and Newton's 3rd law of MOTION mentioned above, it's a no brainer.

Force = Mass x Acceleration

Take a 240gr .44 magnum bullet leaving the muzzle at a healthy 1745 fps. Now compare that to a 55gr .22-250 bullet leaving the muzzle at 3600 fps.

.44 magnum
Mass = 240gr
Velocity = 1745 fps
Energy = 1621 ft-lb

.22-250
Mass = 55gr
Velocity = 3600 fps
Energy = 1581 ft-lb

So the muzzle energy values are similar but due to the difference in mass and muzzle velocities, both bullets require different amounts of force to accelerate them to their respective muzzle velocities. The shooter is going to experience the equal and opposite force that is generated by the burning powder. The time over which that force is felt will have a HUGE effect on perceived recoil. Impulse is the change of acceleration wrt time i.e. dA/dt.

Call F1 the force required to accelerate the 240gr bullet, and F2 the force to accelerate the 55gr bullet and assume that the time-in-barrel for each bullet is the same, then ....

F1 = M1 * A1 (240gr bullet)
F2 = M2 * A2 (55gr bullet)

M1 = 4.36 * M2

Since A (acceleration) = dV/dt and V1 = 0.48 * V2, then ...

A1 = 0.48 * A2

Therefore, F1 = (4.36 * M2) * (0.48 * A2)

F1 = 2.12 * M2 * A2

F1 = 2.12 * F2

So with a few assumptions, the force required to accelerate a 240gr bullet to 1745 fps is 2.12 times greater than the force required to accelerate a 55gr bullet to 3600 fps. If you enter the appropriate values into the recoil calculator at Handloads.com (http://www.handloads.com/calc/recoil.asp), you get the result that the free recoil energy for the .44 Magnum is 12.09 and the free recoil energy for the .22-250 is 5.23 (7lb rifles in both cases). In other words, the recoil energy of the .44 Magnum is 2.31 times greater. That's very close to the 2.12 value I calculated.

So is it really that surprising that a .44 Magnum rifle has a lot more recoil compared to a .22-250 rifle. As has been mentioned, other variables come into play in determining "felt recoil" such as the weight of the rifle, the type of recoil pad, the size of the shooter, the shooting position etc.

:)

dullh
July 12, 2009, 07:00 PM
Recoil is a physical characteristic for sure, but it's more mental and individual than anything else. Recoil is a personal perception, and one would be advised not to acquire more rifle than one is comfortable with. For me, my personal limit is the .375 H&H Magnum. Now the "biggest" rifle I have is a .300WSM, but I have fired a friend's .375 and will say that's about as much as I am willing to tolerate and still successfully hit my target over and over again.

If you enjoyed reading about "Recoil question" here in TheHighRoad.org archive, you'll LOVE our community. Come join TheHighRoad.org today for the full version!