[MikePGS]

I asked this question some time ago in the autoloader forum, but i'm more curious now about in a revolver. It seems that a lot of the carry revolvers are 4", and i'm sure it would be more comfortable than a 5. So would a 4" provide sufficient velocity in order to be as good for SD as a 5?

[Drail]

It depends on how you define "sufficient velocity." For expansion with hollowpoints check with the bullet manufacturer. For heavy cast lead bullets read Elmer Keith. I use a 3 in. .44 spl and get about 850 fps. With at least 200 grain bullets that should be enough. Hollowpoint or cast.

[parisite]

My opinion only now, I feel with 45acp barrels under 4'' I would strive for maximum penetration of a FMJ or SWC instead of trying to mushroom a hp.

The bullet is already .45" and won't shrink.

Shot placement is King, penetration is Queen.

[pinkymingeo]

No problem if you load your own. When I got a chrono, I was really disappointed in factory ammo performance in my 2 3/4" 325PD. The premium 230's have trouble making 800fps. Did a little experimenting. My carry load pushes a 200gr swc at 940fps, which is plenty to do the job.

[jgo296]

lets see i carry a 2.5 inch 44spec
never shot at anyone but imagine if i did they wouldnt out run it

[Oro]

It should be 2 or 2.5" in my opinion. Speer used to publish (may still, don't have the last few editions) data on 2.5" vs. 6" revolver velocities - especially for the .357. They also published .38 special data for 2" vs. their standard test length. Also, their data is/was from guns, not from "test" barrels without a b/c gap, so it was "real world." The velocity difference between even the 2.5" and 6" with identical loads was less than 100 fps - and these were at magnum velocities. With sub-sonic rounds, the difference was about 50fps on average.

If I were to carry a .45acp revolver, I'd want the S&W 25 in a 3" tube - I have one in .44mag that length (629) and it handles/points/balances very nicely. Very, very nicely. It's a real smooth shooter with .44spcl rounds (loaded to standard .45acp levels - 240gr @825fps). It's still a big gun, so it's not super-easy to conceal, even with a short barrel. Open carry is not a real problem. If you want power in something concealable, to me, the 2.5" .357 K-frame is the dream gun.

[rcmodel]

If you do the math, you will find a 4" .45 ACP revolver has 3/4" more "barrel length" then a 5" 1911.

An auto pistols barrel is measured from the breach face to the muzzle.
A revolvers barrel is measured from the front of the cylinder to the muzzle.

So, the 4" revolver really has a longer "bore" then a 5" auto pistol.

In actuality, they get almost the exact same velocity as the auto, despite the slight loss from the barrel / cylinder gap.

rcmodel

[RustyShackelford]

I'd say for most factory ammo in .45acp, you get the best specs from at least a 4" .45acp barrel. Compact/short barrels and some ammo designs have improved greatly in the last 10 yrs but if you want to be safe, stick with at least a 4" barrel.

Rusty;)

[BlindJustice]

rcmodel -check your math.

I have a
S&W 625 5" Bbl. - that is measured from the forcing cone entry point to
the muzzle. so approx. 5" of rifling.

S&W 1911 5" Bbl. but includes the 0.898 inch length of the .45 ACP case
so it has 4.1" max rifling. which last I checked would be the
equal of a 4" Bbl. revolver which has some pressure loss due to the
barrel to cylinder gap.

Of course velocity is somewhat variable in guns of the same type and
barrel length but generally the 5: revolver with it's barrel to cylinder
pressure loss has about the same velocity for the same load out of a 5:
1911.

what was this thread about again...?

[rcmodel]

rcmodel -check your math.My math is fine!
I'm not talking about rifling length.
I'm talking about bore length.

The revolvers cylinder is part of the bore, just as the auto's chamber is part of the bore.

As I said before, a 4" S&W .45 ACP revolver has a longer "bore" then a 5" auto pistol.

rcmodel

[RyanM]

RCmodel is quite correct. Just as a point of comparison, distance from the muzzle to the breech face on a Ruger SP-101 is 3.94", despite the barrel length being 2.25". That means that the distance to the tip of the bullet, for a round that's the maximum OAL, is 2.35". A 0.68" long bullet (about right for a 158 gr JHP, I think, though I don't have any on hand to check) thus has 3.03" to accelerate.

So comparing that to an auto in, say 10mm, since that's roughly comparable in power. 2.35" to the tip of the bullet is equal to a 3.61" barrel. Going by distance the bullet can accelerate, and a 0.64" bullet (about right for a 180 gr JHP), 3.65".

I'm fairly sure that 99% of the .45 ACP revolvers out there use a .44 mag/.45 LC frame, so the cylinder's going to be about 1.7" long. To get the same effective barrel length as a 5" automatic barrel, you need 3.3" of revolver barrel, plus a little bit to compensate for the cylinder gap.

And to address the original question, these are my calculated velocities for various .45 ACP barrel lengths. I have pretty good confidence in my calculator, for producing general rule-of-thumb numbers.

230 gr standard pressure (rated at 850 fps from 5")
7.7" (6" revolver) - 920 fps
6.7" (5" revolver) - 900 fps
5.7" (4" revolver) - 870 fps
5" (full size 1911) - 850 fps
4.7" (3" revolver) - 840 fps
4.25" (Commander) - 820 fps
3.7" (2" revolver) - 790 fps
3" (Officer's mod) - 740 fps

230 gr +P Double Tap Ammo (rated at 1010 fps from 5")
7.7" (6" revolver) - 1110 fps
6.7" (5" revolver) - 1080 fps
5.7" (4" revolver) - 1040 fps
5" (full size 1911) - 1010 fps
4.7" (3" revolver) - 990 fps
4.25" (Commander) - 960 fps
3.7" (2" revolver) - 920 fps
3" (Officer's mod) - 860 fps

It's up to the reader to decide what sufficient velocity is, and thus the minimum barrel length.

[Moonclip]

Heck I get nervous under 5"! I'd noit want to go under 4" though personally though some like short barrel .45acp's I don't due to bullet performance issues and reliability issues.

As for the length of a .45acp revolver for ballistic computations I like to include the cylinder length for this though you also have to figure in the flash gap.

[S&Wfan]

Hi,

I've won a bunch of bowling pin matches through the years with this chopped (down to 3 1/4") barrel S&W Model 25-2 revolver in .45ACP.

It blows 'em off the table with sufficient authority. I also shot matches with my 5" M625 which, of course, had a higher velocity to the bullets it launched.

However, the 3 1/4" M-25-2 is one of the best handling wheelguns I've ever put my hands on and . . . if the SHTF one day and I have to grab a handgun, THIS is the one I want in my hand!!!

http://216.77.188.54/coDataImages/p/Groups/363/363373/folders/277718/2220845IMG2474-2.jpg

The .45ACP cartridge already uses a big, heavy bullet. It WILL get the job done, with proper bullet placement. I'd bet my life on it.

T.

[MikePGS]

Sorry to bump an old thread, but does the same thing apply to say a 610? ie is a 4 inch 610 the equivalent of a 5.7 inch semi-auto 10mm?