Are Some Pistol Calibers Inherently Accurate?

[TunnelRat]

Hi all,
I ask this because it is an ongoing debate between my best friend and I. His first gun ever was a SIG P220 and it's remained his only pistol. Naturally he shoots it very well (beware the man with one gun). He's of the opinion that the 45ACP is more inherently accurate than say the 9mm or 40SW. Now I have to admit of the pistols I own, the ones I shoot the best, slow fire mind you, are in 45ACP. But I think that's a result of the guns themselves. For many people their exposure to the 45ACP comes from the 1911 platform. We're talking a generally tight fighting Single Action Only pistol. To me the design of this pistol is what leads to the accuracy with it and some folks transfer this apparent accuracy to the caliber. As for my friend, SIGs are also very accurate pistols and his also has a trigger action job from SIG and the Short Reset Trigger. Comparing this against a stock pistol is a bit one sided.

What do other folks think? Is there anything about a certain pistol caliber that makes it inherently more or less accurate?

-TR

 

[Jim Watson]

Calibers are not "inherently accurate." Not at the pistol level, although benchrest shooters will tell you the 6mm PPC is the way to go in a 100-300 yard rifle.

The difference is in the amount of development they have had.
When the Beretta was allowed in CMP/NRA Service Pistol matches, 9mm got a lot of attention, as did the guns. The guns and loads have pretty well caught up with .45 ACP.
There is no true precision application for .40 so it has not gotten the work and is seldom regarded as extremely accurate. It is plenty good enough for an "upper A panel" in USPSA, but that is not the same thing as the X ring at 50 yards.

 

[csmsss]

I think the .45 ACP tends to be very accurate, but it has a big advantage in that it's a low pressure cartridge pushing a heavy pill and doesn't have to be pushed out the muzzle at super high velocities to do its thing. Other chamberings, particularly 9mm, don't have that luxury. The higher the velocity of the bullet, the more deviation from average velocity you're likely to experience, and that will, of course, have an effect on accuracy.

But...for practical shooting, all of this is meaningless. Most of us shoot handguns at short ranges of less than 50 yards, where other factors have a much greater contribution (or detriment) to potential accuracy.

 

[dgludwig]

I agree with the above two excellent responses but if there is such a thing as an "inherently accurate" pistol cartridge, I would nominate the .45 ACP and the .38 Special. I suspect, however, that as Jim Watson opined, the reason they might be "more accurate" is the "amount of development" they have both had over the past century or so.

 

[Seaman]

I didn't know there was a 38 spl semi-auto pistol. Learn something new every day.

I handload a lot, for me its mostly about bullet construction, and the most accurate across the counter semi-auto pistol cartridges are the 45ACP and 40S&W.

 

[TunnelRat]

The difference is in the amount of development they have had.

I think that's an interesting point and I can definitely see it being a factor.

Now the 40SW has certainly been around less than the 45ACP and 9mm, but let's compare just the last two. The 9mm luger, 9x19 parabellum, was actually designed a few years before the 45ACP. But they were designed for all intents and purposes at roughly the same time. Yet when I hear claims of accuracy I usually hear it weighted in favor of the 45ACP and not so much the 9mm.

 

[Seaman]

You're right TunnelRat, but the 45ACP is very accurate, think Browning serendipidously discovered the near perfect semi-auto pistol cartridge re brass case volume, powder load and bullet weight/size.

Shouldn't be as good as it is, maybe that's why it is still so popular.

 

[dayman]

All else being equal (so, never) I'd think a faster, more aerodynamic projectile would be more inherently accurate as it would be less effected by environmental forces.
It makes sense that a rounded .45/9mm would be more inherently accurate than a flat-nosed .40, but I don;t think that's a function of the diameter of the projectile.
So, in general, and for all practical purposes, I'd say no.

 

[lcpiper]

Increase the scale of your calculations, imagine a 105mm projectile like from a howitzer. The projectile is very heavy so if you are off by a couple of grains of powder in one bag of propellant, how much of a difference would it make? Not much right? the same is true at the small pistol caliber level.

It's about the projectile mass and how small variations in powder and even weather conditions can have on it's trajectory. The greater the mass of the projectile the great a deviation required to make a measurable difference.

At the same time we are not talking about huge differences. Given that the most used platform for .45ACP is the 1911, I would have to say that this solid platform, coupled with it's SA trigger, is a large contributor to many people's belief in the .45ACP being an accurate caliber.

BTW, how does belief factor in?

If I believe my handgun is accurate, and I believe my ammo is accurate, will I be accurate? You get my drift.

 

[Skans]

All I can say is that I am more accurate with 9mm than any other round. Of course, the gun (and shooter) makes a huge difference. I am more accurate with a Sig X-Five 9mm than I am with a Ruger Mark II .22LR with target barrel.

I'm pretty accurate with an EAA Stock 10mm too, but recovery after each shot is longer for me than with 9mm.

 

[loose_holster_dan]

pistol ammo?
5.7x28 comes to mind.
357sig maybe.

inside 30ft, it's all the same to me. out further, in pistol ammunition, the lighter, hotter rounds tend to have a flatter trajectory. you really aren't reaching the kind of velocities you might see in some rifle rounds that become unstable at certain speeds without the correct twist of rifling.

 

[Technosavant]

I once read that bigger calibers are easier to make accurate. Part of that is for the reason lcpiper points out- small deviations are made more insignificant as the overall size increases. Another possible reason was that it was easier to produce consistent larger caliber projectiles; the larger the bullet, the easier to manufacture them to a given spec for just mechanical/production reasons (not sure how correct that really is though).

I would honestly think that the platform has more to do with accuracy than the inherent nature of the cartridge, and the shooter most of all.

 

[TunnelRat]

I once read that bigger calibers are easier to make accurate. Part of that is for the reason lcpiper points out- small deviations are made more insignificant as the overall size increases. Another possible reason was that it was easier to produce consistent larger caliber projectiles; the larger the bullet, the easier to manufacture them to a given spec for just mechanical/production reasons (not sure how correct that really is though).

Good points, thanks for sharing!

 

[loose_holster_dan]

I once read that bigger calibers are easier to make accurate. Part of that is for the reason lcpiper points out- small deviations are made more insignificant as the overall size increases. Another possible reason was that it was easier to produce consistent larger caliber projectiles; the larger the bullet, the easier to manufacture them to a given spec for just mechanical/production reasons (not sure how correct that really is though).

the part about the % std deviation is correct from an engineering point of view. I see it in my professional career all the time. also, a heavier bullet will be affected less by wind variance, but will suffer more from drag. aerodynamics play into it a lot with smaller rounds. this is why i pointed out that the 5.7 and 357 sig perform well. they are aerodynamically superior to some of the other pistol rounds (while 40 is terrible). however, at the limited range most pistols are fired, these things impact accuracy at a very nominal level.

 

[Ben Dover]

Logically, no caliber is inherenbtly accurate.

Still, I have never seen a quality Colt or S&W in .32 S&W that wasn't amazingly accurate.

 

[BuckRub]

Put almost anything in a Ranson rest and they'll all be super accurate. Then shot in your stance, whatever you prefer only to be disappointed.

 

[James K]

I once read that the most "inherently accurate" center fire pistol cartridge was the .32 S&W Long. So can we expect all the .45 ACP, 9x19, ,40 S&W, etc. owners to trade up to the .32 Long? Or not.

Jim

 

[Wreck-n-Crew]

I once read that the most "inherently accurate" center fire pistol cartridge was the .32 S&W Long. So can we expect all the .45 ACP, 9x19, ,40 S&W, etc. owners to trade up to the .32 Long? Or not.

I am not gonna scratch that itch James!...lol

 

[SIGSHR]

I would say yes. Many factors at work of course-look at how the 38 Super suddenly became accurate when it was found it should headspace on the rim and not on the case mouth. My Browning HP in 9MMP has always been accurate with lead bullets due to its barrel's rate of twist and depth of lands and grooves, my S&W M659 can be very finicky with lead bullets. I suspect that some calibers-38 Special, 45ACP to stick with semiauto calibers-have been subject to more experimentation than say 380 or 25ACP.

 

[Wreck-n-Crew]

I would say yes. Many factors at work of course-look at how the 38 Super suddenly became accurate when it was found it should headspace on the rim and not on the case mouth. My Browning HP in 9MMP has always been accurate with lead bullets due to its barrel's rate of twist and depth of lands and grooves, my S&W M659 can be very finicky with lead bullets. I suspect that some calibers-38 Special, 45ACP to stick with semiauto calibers-have been subject to more experimentation than say 380 or 25ACP

I have seen a 1911 with a 38 super barrel sleeved in side the 45 barrel as a conversion for competition.

I never met the Smith who did it, but it was used in competition through several matches before the barrel insert slid and the thing is a mess now.