Question - Different caliber weights? Pros VS Cons? Etc.

[rodralig]

So, I am coming in to my second year of firearms - going through my first IDPA match and classifier a few weeks back, and am looking to digging deeper into shooting.

The question up then, is what are the difference on bullet weight on a specific caliber? Say, for a 9mm Luger, what are the PROS and CONS among a 115gr, a 124gr, or a 147gr? I've heard that the heavier bullet is flatter, hits higher, more manageable recoil, etc. I hear that competition shooters, for example, prefer the heavier bullet loaded to the required PF (like a 147gr for 9mm; albeit, I somehow prefer the 115gr).

That said, am still trying to understand why I'm hearing that a 40S&W has a stronger (or unpleasant recoil), when, say compared to a 45ACP.

On the side, and most probably getting ahead of myself - either for Minor or Major, why would one anyone go for a specific caliber and weight? I could see in IDPA that there is really no advantage going with Major; but for the other shooting sports?

Thanks in advanced!




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[SteveB]

That said, am still trying to understand why I'm hearing that a 40S&W has a stronger (or unpleasant recoil), when, say compared to a 45ACP.

Chamber pressure for the .40 is much higher than the .45; SAAMI specs are 35,000 PSI for the .40, 21,000 PSI for the .45.

[LtDave]

Heavier bullets often have more momentum and knock down steel more consistently. I shoot both hot 115 grain and moderate velocity 147 grain hand loads based on what shoots best in a particular gun. Some guns will shoot POA/POI with the lighter loads, others with 147 grain loads. In testing a lot of ammo in a lot of guns I've found that those combos are the most accurate in my guns. For some reason, it is rare for me to find a 124 grain hand load that is the most accurate in a particular gun. I don't find .40 S&W all that harsh to shoot, but I've been shooting 180 grain hand loads that make PF, not a lot of full power stuff any more. When my department switched to .40 S&W HK USPs from 9mm S&W 5906 pistols we didn't have any issues with it being too hard to shoot. .40 S&W is a good compromise for USPSA, you can load it up for major ranking or load it down and shoot minor. Saves having to buy different guns to shoot in production and limited.

[Jim Watson]

Felt recoil and gun movement are very subjective. I am at present shooting some 135 and some 147 gr 9mm Minor loads for IDPA ESP. I could get along with 124s but find 115s less pleasant. I CARRY 115 JHPs because I am confident that the brand I use will feed, fire, function, and hit the assailant. I don't want to go to the trouble and expense of getting that comfortable with a different product.

Minor vs Major, caliber vs caliber is match rule driven.
In IDPA the only use for Major is for .45 ACP only in CDP only. Other Divisons shoot Minor, 9mm is much the most common but light .40s or even very light .45s will work.

In USPSA you may shoot 9mm Major in Open only. Other Divisions are .40 minimum for Major loads. So .40 is what is used, more rounds in a 140mm magazine than .45.
There is some 9mm Minor in Limited, I have seen different explanations for that.
(USPSA Production and Carry Optic are scored Minor only, no matter the caliber or actual power factor. Hard to find anything but 9mm there.)

[RevolverRob]

The question up then, is what are the difference on bullet weight on a specific caliber? Say, for a 9mm Luger, what are the PROS and CONS among a 115gr, a 124gr, or a 147gr? I've heard that the heavier bullet is flatter, hits higher, more manageable recoil, etc. I hear that competition shooters, for example, prefer the heavier bullet loaded to the required PF (like a 147gr for 9mm; albeit, I somehow prefer the 115gr).

Bullet weight preferences are dictated by power factor and/or accuracy. For instance, I personally prefer 124/127-grain +P loads for defensive work. Why? I find they shoot very well in terms of accuracy out of my guns. Deviation from 124-127 +P loads is based solely on 1) Availability. 2) Specific purposes, i.e., to meet a power factor or for running in a suppressed gun, etc.

That said, am still trying to understand why I'm hearing that a 40S&W has a stronger (or unpleasant recoil), when, say compared to a 45ACP.

As said before, felt recoil is very subjective and is dependent on your grip, hand/arm strength, and the fit of the gun to your hand. BUT - most of these comparisons are being made between guns with very different physical properties. Not just grip angle, bore height, etc. I mean, physically a .40 Glock weighs less than a .45 1911, by nearly a pound and a half when fully loaded. That's a significant amount of additional mass to soak up recoil energy. Additional factors like peak pressure means that though velocity and mass are different, you may also have a more significant explosion in your hand at a given time. (Bearing in mind that a gun is merely a container for maintaining an explosion and providing directional vectoring onto a projectile).

On the side, and most probably getting ahead of myself - either for Minor or Major, why would one anyone go for a specific caliber and weight? I could see in IDPA that there is really no advantage going with Major; but for the other shooting sports?

All depends on the game. And sometimes what you have access to in terms of affordability or even sponsorship (at upper levels). In ICORE (revolver shooting), one of the hotnesses is 8-shot .357 guns, tuned to run .38 long-colt powder-puff loads that are barely faster than a sneeze, but you can cram a 160-grain bullet into the case, and because of length and powder get it to make the appropriate PF to meet specs, but keep recoil extremely low. It also gives a good length to help with reloading. - This is what it takes to compete and win at some levels. It's up to you to decide when/where/how you draw the line. (And regardless of what judgements people have, you ain't got to have the approval of anybody to draw that line and do what you want in terms of shooting).

-Rob

[andre3k]

That said, am still trying to understand why I'm hearing that a 40S&W has a stronger (or unpleasant recoil), when, say compared to a 45ACP.

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I would think that most people that complain about the recoil of the 40 S&W are shooting defensive loads in polymer frame pistols. If that's the case then you're likely to experience more felt recoil than 9mm or 45. However by handloading a 180gr 40S&W round down to 750-800 fps makes for a very soft shooting and fun round to practice with.



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[5pins]

Here are a couple of articles you may find helpful.

http://www.shootingtimes.com/reloadi...ht-gives-edge/

http://www.shootingtimes.com/reloadi...-compensators/

[DocGKR]

For defensive use, bullet weight and caliber tend to be mostly irrelevant compared to other factors--is the cartridge reliable, accurate, capable of being shot rapidly in field conditions, allow sufficient projectiles in the magazine, and do the projectiles offer adequate barrier blind penetration.

[BehindBlueI's]

That said, am still trying to understand why I'm hearing that a 40S&W has a stronger (or unpleasant recoil), when, say compared to a 45ACP.

Most .45 guns were designed to be .45 guns.

The more common .40 guns were designed to be 9mm guns then adapted to .40.

The speed of the explosion matters as well, and firing a gun is a controlled explosion. While demolitions is more my area than internal ballistics, two explosive charges with different "speeds" behave quite differently even if the amount of "power" is the same. A very fast shockwave cuts, a slower shockwave pushes, which is why cutting charges and cratering charges use different types of explosives. The relatively slow speed of the .45 lengthens the amount of time the recoil is applied, more of a push than a slap. If that has any effect beyond how it feels to your hand, I've no idea.