Identity problems - number 20XX, triple or 1917 - unsure.

[Tom K]

I think I will try to break it down and give it a good cleaning. I definitely want to shoot this gun! It came with (6) half moon clips, so I can use them to shoot the 45 AR 14,000 PSI ammo (thanks for the advice Hondo)... Stoked to give it a shot

If you can find .45 Auto Rim, you don't need the clips. That is the whole reason for the existence of .45AR, to be able to shoot .45ACP revolvers without the need for clips. The .45AR is dimensionally the same as .45ACP except it has a thick rim for correct headspace, and the rim is larger in diameter than the body (as opposed to the "rimless" design of the ACP round) to allow for extraction.

I am puzzled to read here that AR rounds are loaded to a lesser pressure than ACP rounds, since they were meant to be used in the same guns. Does anyone have a reliable source that verifies this information?

*Edit: Okay, I just checked the specs (ANSI/SAAMI Z299.3-1993) for .45ACP and .45AR. They show:

45 Auto: 230gr MC-FMC, 830fps, 18,000 CUP (Copper Units Pressure)
45 Auto Rim: 230gr Lead, 825fps, 15,000 CUP

It does indeed show that AR is loaded to a lower pressure than the ACP round, and normally with a lead bullet rather than jacketed. Unfortunately since .455 is not an American cartidge there are no SAAMI specs for it.

 

[Hondo44]

Tom,

Actually the ACP was not designed for the revolver, but for the 1911 and the wheelgun was designed for ACP with a heat treated cyl by government contractual requirement. Then after WW I, the 45 AR was designed for the revolver.

 

[Tom K]

Tom,

Actually the ACP was not designed for the revolver, but for the 1911 and the wheelgun was designed for ACP with a heat treated cyl by government contractual requirement. Then after WW I, the 45 AR was designed for the revolver.

Jim, I didn't mean that the .45ACP was designed for the revolver - I know that it was designed by Browning for the 1911 automatic. I meant that, since the 1917 S&W and Colt revolvers were designed to accept the ACP round, that it would seem that the AR would have the same internal ballistics as the ACP. Why specify a lower pressure for the AR round when it is used in the same guns (revolvers) as the ACP?

My guess (and it's only a guess) is that the AR was in fact specified to a lower pressure by SAAMI in deference to converted .455s and such. Which seems silly, since the vast majority are probably going to use the more readily available ACP ammo. It probably seemed like a good idea at the time....

For what it's worth, the other primary caliber that the S&W Hand Ejector revolver would be chambered for at that time is the .44 S&W Special, and its operating pressure is 14,000 CUP (as is .45 Colt). Of course these are specs from 1993 - no telling what pressures they thought they were getting in 1917.

 

[Hondo44]

Jim, Why specify a lower pressure for the AR round when it is used in the same guns (revolvers) as the ACP?

My guess (and it's only a guess) is that the AR was in fact specified to a lower pressure by SAAMI in deference to converted .455s and such. Which seems silly, since the vast majority are probably going to use the more readily available ACP ammo. It probably seemed like a good idea at the time....

For what it's worth, the other primary caliber that the S&W Hand Ejector revolver would be chambered for at that time is the .44 S&W Special, and its operating pressure is 14,000 CUP (as is .45 Colt). Of course these are specs from 1993 - no telling what pressures they thought they were getting in 1917.

Tom, oh sorry, now I understand. That's a good question and I don't know the answer. Your guess is as good as any and makes sense to me.

The 44 Spl and 45 Colt were always in the 14,000 range. Although the original 45 Colt with blackpowder (40 grs IIRC) was the hottest load. But not likely any higher pressure due to the blackpowder.

 

[Ballarat]

Be mindful of the fact that the cylinder was originally designed for the 455 Eley cartridge, which military loading was a 260g hollow based LRN projectile at about 630FPS. There were other projectiles used also.
It should be fine to shoot with 45AR brass, but keep velocity to the low 700FPS range or less with a 230g LRN design projectile. The sights would have been regulated for the military loading.

Starline makes 45AR brass and I use 45ACP reloading dies and apply a light taper crimp. The AR dies will apply a conventional roll crimp, but using 230g LRN designed for the 45ACP which mirrors the RN 45ACP hardball projectile I thus prefer the ACP dies, due no crimping groove on those projectiles.

Hope evreything turns out well and you get the old girl shooting again.

Rgds
Bob