inherent accuracy

[Armored farmer]

I have been reading of late about certain calibers possessing inherent accuracy qualities. .17HMR. .204 Ruger. 20 gauge slugs....
You know the 'golden mean' theory.
My particular question.....is the 9mm more inherently accurate than .45acp. ?

 

[Drail]

Not in my experience.

 

[bannockburn]

Not really, at least as far as my shooting experiences have been. My three most accurate semi-autos (Colt Gold Cup,customized Combat Commander, and Browning BDA), have all been .45s.

 

[jmr40]

With MOST cartridges the longer they've been around, and the more they are used in competition the more likely you are to find better accuracy.

I think it has less to do with the actual cartridge, but the fact that gun and ammo manufacturers have had more time and incentive to develop accurate guns and loads.

I'd think 45 and 9mm will both prove to be slightly more accurate on average than most other semi-auto rounds for the reasons stated above. Many shooters may find that they shoot 9mm better because of less recoil, but I think the 2 cartridges potential is the same.

When you start talking about rifle cartridges much of the above applies too. But there are some cartridge designs that do tend to be easier to squeeze a little extra accuracy out of.

 

[LiveLife]

With MOST cartridges the longer they've been around, and the more they are used in competition the more likely you are to find better accuracy.

Bingo, not to mention the refinement of pistols like 1911 for 45ACP. While sub 2" at 25 yards is rather readily achieved by many 1911s with known accurate loads (and cleaner SA trigger doesn't hurt either), I have to really work at reducing my 9mm/40S&W groups, often based on my own trial & error load development - http://www.thehighroad.org/showthread.php?p=9924922#post9924922

45ACP shot with Sig 1911 (shot groups at 25 yards unless specified as 15 yards)

9mm shot with Glock 22 and KKM/Lone Wolf 40-9 conversion barrels

40S&W shot with Glock 22

 

[Sam1911]

Most of the truth behind this theory has to do with combinations of factors (e.g. the guns the round is commonly chambered in, the type of shooting most commonly done with this cartridge, etc.), rather than the specifics of a certain cartridge.

As others have said, there's been A LOT of precision bulls-eye shooting done with .45ACP. So it has a reputation for being very accurate. Well, duh. Put that much work, for that many years, into squeezing groups down and you'll have a very accurate cartridge. Doesn't mean that the .45 is inherently more accurate than 9mm or .38 or 10mm or anything else. The road is just well-trod.


Now, in the upper tier of benchrest rifle shooting there are very worthy debates about the inherent properties of the various cartridges used for that sport. Those guys are really talking about almost immesurable differences that could/might produce a win, and they're trying to isolate every piece of human influence out of the equation so that mechanical accuracy can shine through.

That really doesn't apply to service handguns and the cartridges they shoot.

 

[ATLDave]

I have never heard a remotely plausible explanation based in actual physics for why any particular straight-walled pistol cartridge ought to be any more or less inherently accurate than another.

 

[SSN Vet]

There are likely a couple ingredients to "inherent accuracy"...


Some cartridges were created in conjunction with new firearms designs. The classic example is the .45 acp and the 1911. In this instance, the .45 acp has probably acquired a reputation for inherent accuracy riding on the coattails of the 1911 platforms excellent SAO trigger mechanism.

Another example is 5.56x45 and the AR-15 platform, where the excellent peep sights, which many find their eye intuitively aligns, give both the rifle and the cartridge a reputation for inherent accuracy.

Then within a given cartridge (i.e. 9x19) the heavier bullets may prove to be more accurate, which is influence by the fact that they have more surface area in contact with the rifling. They also will also have more inertia. Both of these affects will require the gas pressure will rise to higher levels, and the rounds will obturate and conform to the rifling better. Heavier bullets will also be less affected by windage, and longer bullets usually have a better ballistic coefficient.

just a couple thoughts from someone not claiming to be an expert.

 

[ArchAngelCD]

Like already mentioned, practice enough with any cartridge and gun and unless there is something wrong with the gun you are shooting you will improve your accuracy. It ain't the cartridge, Its the quality time behind the trigger...

 

[Zaydok Allen]

Awhile ago I was trying to understand the idea behind inherent accuracy, so I started a thread. It trended more so towards rifle cartridges, but it was an interesting conversation none the less.

If anyone cares to read:

http://www.thehighroad.org/showthread.php?t=774598

 

[trentcwwilson]

All this talk of pistols, yet he named rifle rounds. If you go the rifle caliber route, hard to beat 222 Remington(not magnum). I've been dying to try out my single shot 222, but I can't find factory ammo around here. As far as the 204 ruger, I've seen them hit or miss. And being a non standard cartidge, who knows if it'll be around in 5 years.

 

[LiveLife]

is the 9mm more inherently accurate than .45acp.

We are still working on OP's 9mm vs 45ACP accuracy question.

 

[trentcwwilson]

We are still working on OP's 9mm vs 45ACP accuracy question.

My bad. I need to learn not to skim. In my case, yes and no. Slowly firing off rounds, I'm extremely accurate with my 45. But when it comes to speed, I cannot group my Kimber Warrior SOC like I can my ported M&P 9 Core.

 

[LeonCarr]

IME one is not more particularly accurate than the other.

Per Irv Stone of Bar-Sto Barrel Fame of all the barrels he has built and chambered the most consistently accurate autoloader cartridge is the 10MM and the most consistently accurate revolver cartridge is the .38 Special.

Just my .02,
LeonCarr

 

[Saleen322]

My particular question.....is the 9mm more inherently accurate than .45acp. ?

In my experience, no. I have accurate pistols in both and it took more work for me to get the 9mm to shoot with the 45. I have good 9mm loads now but it does not seem as easy to achieve.

 

[trentcwwilson]

In my experience, no. I have accurate pistols in both and it took more work for me to get the 9mm to shoot with the 45. I have good 9mm loads now but it does not seem as easy to achieve.

I'd love to see how accurate both mine would be if I handloaded for them.

 

[Armored farmer]

It sounds like the old .45 is still hard to beat for accuracy potential.
I began wondering about this when I started getting the itch to build an AR in 9mm. I swear by my .45 acp 1911s , but if I build a 9mm carbine. ....then you know that it's just a matter of time til I have a 9mm pistol.

 

[trentcwwilson]

It sounds like the old .45 is still hard to beat for accuracy potential.
I began wondering about this when I started getting the itch to build an AR in 9mm. I swear by my .45 acp 1911s , but if I build a 9mm carbine. ....then you know that it's just a matter of time til I have a 9mm pistol.

I bit the bullet, pun intended, and bought a 9mm. I'll never carry one, but it may replace my 1911 as a comp gun.

 

[larryh1108]

I have never heard a remotely plausible explanation based in actual physics for why any particular straight-walled pistol cartridge ought to be any more or less inherently accurate than another.

I think it has more to do than the inherent characteristics of a given round.

e.g. My CZ PCR is more accurate with a 124gr bullet than a 115gr bullet even though both are 9mm bullets.

I think how a round mates with a specific barrel can make it more inherently accurate because there are different twist rates, chamber sizes and a bullet's ogive. CZs are known to have a shorter chamber than other 9mm barrels so the leade, where where the bullet jumps from the chamber into the rifling, is shorter than a Glock or S&W. A shorter and fatter 9mm bullet may contact rifling sooner than a bullet with a longer but thinner tip. This also affects accuracy as well. Some 9mm rifling may be 1/10" and another can be 1/9.84". Each company makes their own decision based on a specific bullet weight and their own testing. It does make a difference.

All of this is considered in reloading.

So, stating a certain cartridge is more inherently accurate than another size cartridge may be based on a lot of different variables because ammo comes in different shapes and sizes within a specific caliber. It's too broad of a statement to be valid.

 

[sequins]

9mm typically goes from supersonic to subsonic midflight, making it inherently less accurate than a round which leaves the barrel subsonic and does not make such a transition. I still prefer and would carry 9mm over 45acp but that just seems obvious to me...

 

[LiveLife]

9mm typically goes from supersonic to subsonic midflight, making it inherently less accurate than a round which leaves the barrel subsonic and does not make such a transition.

We talked about transonic effect on accuracy on H&R category but how do you explain the 1.25"-1.5" @ 50 yards shot group rating of Atlanta Arms 9mm PPC/AMU loads that are used by match teams and US military teams?

9mm 115 gr XTP PPC load @ 1100 fps rated to 1.25" groups at 50 yards - http://atlantaarms.com/products/9mm-115gr-jhp-match.html

9mm 115 gr FMJ AMU load @ 1150 fps rated to 1.5" groups at 50 yards - http://atlantaarms.com/products/9mm-115gr-fmj-match-amu.html

 

[2zulu1]

I have never heard a remotely plausible explanation based in actual physics for why any particular straight-walled pistol cartridge ought to be any more or less inherently accurate than another.

I don't know either; however, you may want to talk to the tech people at Sierra bullets.

From the Sierra #5 reloading manual;

The 10mm is an inherently accurate caliber that routinely gets 1" ten shot groups @50 yards through a Colt Delta Elite during quality control testing.

The 45auto routinely gets 1.5" ten shot groups @50 yards through a Colt Gold Cup National Match.

I have three 9mm pistols; G17, BHP and a Beretta M92 FS Brigadier INOX, but I haven't tested them for accuracy at distances compared to a Colt Government in 38Super, which also seems to be an inherently accurate caliber.