Heavy vs. Light Bullets

[LCPor9mm]

Really

OK - there seems to be a little disagreement as to the more effective bullet weight.

That may qualify as an understatement.

If I use 115 gr FMJ as my range ammo, should I expect different performance if I use 147 gr JHP?

This should be obvious to you by now.

This is a little over simplified but here's what you do. Research and select 6 different types of carry ammo weighing between 124 and 147 grains. Buy 50-100 rounds of each, take that and your practice ammo to the range and shoot it. POI may vary considerably, but what you are looking for is consistency. When you find one or two you and your gun both like buy more of that and shoot a little of it everytime you go to the range, along with your cheaper practice ammo.
Another method you might try is to buy hardball practice ammo in a similar weight as your carry ammo, again what you are looking for is a consistent POI in relation to your practice ammo. This is what I did in my .223. The really cheap 55 grn ammo was consistently off by 2" from the 69 grn my rifle liked. I got tired of dealing with it so I started buying a cheap (unfortunately not as cheap as the 55 grn) 69 grn practice ammo to shoot and have had very good results with this method.

 

[blinkjr]

Thanks again for the follow-up replies.

Prosser - I have been to the range once. 100 rounds Federal Champion 115 gr FMJ through it. No problems - still learning to properly load the magazines. (I had several that didn't chamber the first round. I think I didn't have the first round properly seated in the mag. Once I started checking that top round, everything was fine...with the gun...the shooter meanwhile.......)

I'll have to take up the suggestion to run different weights through my gun to see how they work. I am far from being good enough to do much side by side comparison, but I need the practice to get proficient. So this will be a good reason to get to the range.

Now, does the 147 gr shoot a little softer than a 115/124?

 

[youngda9]

Winter Heavy. Summer Light.

 

[basicblur]

No problems - still learning to properly load the magazines.

Should you ever spring for a magazine loader, get an UpLULA.
Despite 'Net chatter, there are very few 'best' in the usual arguments-the UpLULA is one of the few that probably is the best in its category.

I assume you're a new shooter? If so, don't overlook the benefit of lots of dry fire practice. The SP2022 lends itself to dry fire practice well (no cycling the slide for each shot). The DA of the SP2022 is excellent AFA teaching trigger control.

 

[blinkjr]

basicblur - I'm already ahead of you. I bought an UpLULA at the LGS/Range when I shot. Once I was shown how to use it properly, I realized why it got the rave reviews.

Again, I don't believe it was a mechanical issue. It was more learning how things are supposed to be and being a newbie. I just need a lot more range time.

 

[Prosser]

Recoil is determined by bullet weight, powder type and speed, and gunweight.

I hate to tell you this, but 9MM DOESN'T RECOIL.

The area of recoil figures can be calculated here:

http://www.beartoothbullets.com/rescources/calculators/php/recoil.htm

What you will find is ammunition companies have two goals: Sell lead at gold prices, number two is to find the powder that allows the most profit possible.

If you buy cheap ammo, expect cheap powder, not suited to the task at hand. Be happy if it goes bang, and cycles the gun.

Do not associate recoil with velocity. Cheap powders can give horrible recoil,
yet not be suited to the barrel length, and give little velocity.

While a pain to load for, unless you have little fingers, I'd suggest either getting a Dillon 550 and learn to reload, or find a cheap ball ammo, or flat point ammo you can buy in bulk, and shoot that.

One thing the recoil and ft-lb calculator will show you:
The very limited range the 9mm functions in, and, that is even further limited by running it in an auto pistol. In other words no magic bullet is going to make up for the fact it's 9MM. It's not a .357 out of a 4" barrel.
It's not a .44 Magnum.

War pistols are designed to get you back to your rifle, or provide dinner in a pinch. Where 9MM shines is allowing you to hit a target with multiple shots,
quickly. Plan on volume to do the damage, not a single shot.

 

[481]

This is incorrect.

I hate to tell you this, but 9MM DOESN'T RECOIL.

Sure it does. BB guns through naval guns; all calibers produce recoil.

 

[Loosedhorse]

9MM DOESN'T RECOIL

I'm confused by this claim.

Also, we should consider the difference between "actual" recoil and "felt" recoil. I have a friend who cannot tolerate 9mm out of a Beretta 92, because the large frame gives her a bad grip. Give her a K-frame, and .357 is no problem.

From a "felt recoil" perspective, no, I don't think a "147 gr shoots a little softer than a 115/124." It's usually quieter, though.

 

[Prosser]

Figure of speech. Run the recoil numbers on 9mm, and you can see why it's not classified as a major caliber.

 

[2zulu1]

Figure of speech. Run the recoil numbers on 9mm, and you can see why it's not classified as a major caliber.

I've run some 9mm handloads through recoil software and from a G17,
Range was from about 6ft/lbs to about 9+ ft/lbs. Some full power 357mag/M686/6" loads are also in the 10 ft/lb range.

 

[Prosser]

The sig is 29 oz, unloaded. Add ammo, and the weight of the gun is going to soak up any real recoil.

Run any combinations of 9MM out of that gun, and look at the recoil figures and post them.
The only chance of 9mm have affecting recoil is in a Kahr PM9(18 oz. or lighter gun).

 

[coolluke01]

Drail
"If I told you that you were going to be in a car crash and you got to pick what kind of vehicle was going to broadside you - either a Honda Civic or a Peterbuilt semi with a maximum load - which one one would you choose?"

Since 115 gr move much faster than 147 gr in your analogy the semi approx 80000 lbs and the civic 2800 lbs should not be traveling at the same speed. The semi is 28.5 times heavier. If the Semi was traveling 10 mph the civic would be going 285 mph. I would pick the semi.

If 115 gr and 147 loads have the same amount of powder (which they don't, the 115 can hold more since there is more room in the case.) The foot lbs of force will be the same at the muzzle. The 147 will be moving slower and the 115 will be moving faster but the amount of potential energy will be the same in each bullet.
115 gr loads can hold more powder so they can actually achieve higher foot lbs of force.
I shoot steel matches with 100 gr bullets and it knocks them down just as well as 115's or 124's. I have moved to 124's now because they cycle my gun better.

 

[Loosedhorse]

Range was from about 6ft/lbs to about 9+ ft/lbs. Some full power 357mag/M686/6" loads are also in the 10 ft/lb range.

Recoil energy is one aspect of recoil; recoil momentum (impulse) is another. In my personal experience, felt recoil has more to do with impulse than energy, but that will vary.

Typical 115 9mm+P+ (1300fps) load will have about 430 ft-lb of energy and 0.66 lb-sec of impulse momentum; a 147 +P+ will go 450 and 0.77. A 125 .357 (1500) load will run about 624 and 0.83; a top-end 180 will do about 900 and 1.2.

 

[blinkjr]

Thanks again to all, and Merry Christmas!!!

Well, looks as though this has run its course. Thanks everyone for your input. I'm not sure I got any consensus, but definitely informative.

I think I'm going to try 124gr, both for range and JHP. I'm so new to all of this, I'm not sure what I'll notice as different from the 115gr I've shot. But from what I could cull from all the comments is that modern ammo is far superior to older technology. So, as long long as I stay with newer designs, I should be ok.

As most have stated here and in other threads, it's more about location than anything else. That means practice, practice, practice. Hmm, more range time...that's a good thing!

Thanks again to all, and Merry Christmas!!!

 

[Prosser]

One thing for sure:
More choices and less cost with the lighter bullets. More gold is more expensive then less gold.

 

[2zulu1]

Recoil energy is one aspect of recoil; recoil momentum (impulse) is another. In my personal experience, felt recoil has more to do with impulse than energy, but that will vary.

Typical 115 9mm+P+ (1300fps) load will have about 430 ft-lb of energy and 0.66 lb-sec of impulse momentum; a 147 +P+ will go 450 and 0.77. A 125 .357 (1500) load will run about 624 and 0.83; a top-end 180 will do about 900 and 1.2.

Given bullet weight, velocity and powder weight, recoil can also be measured in feet per second. The magnum load I mentioned had ME of about 740fpe, the Hogue rubber grips softened the 686's recoil considerably.

The high end G17, 125gr Gold Dot, HS-7 1290ish provided a bit of recoil as I mentioned.

 

[Loosedhorse]

Given bullet weight, velocity and powder weight, recoil can also be measured in feet per second.

Actually, no, it can't; not with those givens. However, if you add another given (the weight of the gun that the bullet is being fired from), you can then calculate the "free recoil velocity" of the gun after firing.

People also speak of "recoil impulse time," which is almost equivalent to the interval between ignition of the charge and the exit of the bullet from the barrel. Shorter impulse times often correlate with harsher, sharper perceived recoil.

 

[coolluke01]

Loosedhorse,
Is that why many departments are switching from 40 cal back to 9mm. I've heard it's a much sharper feeling round.

 

[Loosedhorse]

I did not know (and would be surprised to learn) that many municipal departments are switching to the 9 from .40; but I don't know for sure. Massad Ayoob mentioned that (for state police units), 9mm is almost gone (2 states use it), which puts it behind .40, .357 SIG, .45 ACP...and even .45 GAP.

The 9's ability to meet LE penetration and barrier-defeating requirements is only met by a few loads (though more then there used to be). With .40, you've got a much broader choice. Any "resurgence" of the 9 would most likely be due to more available loads that pass LE muster (and of course any "deal" to be had on pistol and ammo cost).

For non-LE, I don't think 9mm will ever fade.

Sharper? 9mm+P+ loads are sharp. Between a 147gr bullet subjected to over 38,500 psi going 1175fp, and a 180 gr bullet subject to 35,000 and going 990, out of essentially "the same" gun? Not sure, but I'd expect the 9 to be sharper.

 

[Bovice]

Does this really need to be stated again? The argument of heavy vs. light is energy transfer. Assume both bullets stop in the target. Kinetic energy is 0.5(m)(v^2). Notice that the velocity term is squared. The difference in mass between 115 to 147 grains is pretty much nothing. When you look at velocities, any difference between the two is magnified since it's a squared term.

The argument of the semi going 10mph vs the civic at 285mph is momentum. The momentum of a bullet in flight is miniscule compared to the momentum potential of a human being. Momentum=m*v. The change in momentum of a human when impacted with a bullet is almost zero.

 

[Prosser]

Just a take on this stuff. First off, the case capacity between the rounds is, at least from reloading data, about 50% more with the .40 using a light for caliber bullet.
In the .40's case, that's a 135 grain bullet, and a 90 grain in the 9mm, using Longshot.

So, you have 50% more powder, and, nearly 50% more bullet weight with the .40, in the same guns that the 9mm was designed to be shot out of.

For a 2 pound gun, the round, at 1300 fps:
Recoil Energy of 7 foot pounds, and Recoil Velocity of 14 fps.

The 90 grain at 1300 fps in a 2 pound gun:

Recoil Energy of 3 foot pounds, and Recoil Velocity of 9 fps.

Great thing about 9mm is it uses so little powder that a really junky powder only shows up with a little more recoil. Maybe the larger capacity of the .40
makes cheap powder more noticeable? Certainly is the case when loading .45 Super/.451 Detonics.

This is where I drag out the 9MM doesn't recoil doll.

I can see where the .40 maybe closer capacity wise to .45ACP. The neat thing about 45 ACP is it's shot in guns DESIGNED for it.

Couple other factors.

With .451 Detonics I noticed the difference in recoil between using really fast powders, medium, and slower. However, I couldn't really use a heavy charge of a fast burning powder because pressure went too high, too fast.
Medium to slower powders gave more of a push, but, they also provided more velocity, so you still ended up with more recoil.

When loading certain calibers you have a pressure point where it seems that you get little increase in velocity for a massive increase in pressure and recoil. The difference between heavy .44 magnum and .454 Casull loads come to mind, using similar bullet weights.

However, there is a point where bullet weight is the main issue in recoil, and over powers any issues with powder types. Your Mileage may vary.

All of these are general experience observations, but, I have limited, old data on loading for 9MM. Don't know if it stands up today.

 

[Loosedhorse]

The change in momentum of a human when impacted with a bullet is almost zero.

I don't think anyone expects a human's momentum to be much changed by a bullet. However, momentum seems to be a major factor determining penetration (others would include retained weight, expansion, final diameter, and projectile shape).

Also, momentum is a major factor in recoil. So that's why it gets talked about.

Agreed: the automotive analogies are poor.

 

[2zulu1]

Actually, no, it can't; not with those givens. However, if you add another given (the weight of the gun that the bullet is being fired from), you can then calculate the "free recoil velocity" of the gun after firing.

People also speak of "recoil impulse time," which is almost equivalent to the interval between ignition of the charge and the exit of the bullet from the barrel. Shorter impulse times often correlate with harsher, sharper perceived recoil.

Given that I was comparing the recoil of handloads fired from G17/M686, I incorrectly assumed that those weights would be plugged into recoil software.