Please help ID this gun

[Mlschnei]

Wow. So much information. My head is spinning.
You guys are amazing. Thank you so much for taking
the time to educate a rookie.

Once I get the ammo in I will look into moon clips, which
I know nothing about.

 

[DWalt]

I will add a caution. Moon clips are used with .45 ACP cartridges which have high operating pressures. I would not recommend using them in that TL, certainly not very often. If .45 Colt cartridges (Cowboy) fit OK, and they may or may not, I would use them. .45 AR cartridges are not easy to come by, and have the same potential pressure problem as the .45 ACP. Would be nice to have some shooting friends who could supply you with various cartridge sizes to play with.

 

[Hondo44]

Good idea.
Although the 45 Cowboy is too short being the same length as ACP. So the cartridge would chamber too deep in the shortened cylinder the same as 455 MKII, and would also require a moon clip spacer. However, because it has a thicker rim than 455 (.015” thicker) and I’m told the triple lock firing pin is a bit longer than modern Smith revolvers it just might work.

45 Schofield cowboy ammo would work better. It’s longer, about the same length as 455 MKI and also has a thicker rim. The 455 MKI shoulder in the chambers will keep it from going all the way into the shortened cylinder. And the rim would not rest against the face of the shortened cylinder.

45 AR is perfectly safe to shoot in that gun, It is not factory loaded to the high pressure of 45 ACP BECAUSE it’s not designed to operate the slide of the 1911 semi auto pistol!

 

[DWalt]

I am still curious about the possibility of a .45 AR conversion as stamped. I cannot imagine that it would have been done in England, or indeed anywhere else in the world other than the USA. It is about as uniquely an American cartridge as you can find.

 

[Hondo44]

I also can’t imagine it being done in England either. It’s not the first time I’ve seen a 455 converted to and specifically marked only for 45 AR. Although of course it allows the use of ACP, I consider it a case of a conscientious gunsmith making the point that the conversion was specifically for AR and to differentiate it from ACP. Because the ACP pressure rating is about 25% higher than AR and what the gun was designed for as being safe.

 

[Muley Gil]

I also can’t imagine it being done in England either. It’s not the first time I’ve seen a 455 converted to and specifically marked only for 45 AR. Although of course it allows the use of ACP, I consider it a case of a conscientious gunsmith making the point that the conversion was specifically for AR and to differentiate it from ACP. Because the ACP pressure rating is about 25% higher than AR and what the gun was designed for as being safe.

Jim, normally I agree with what you post. However, I truly believe that when this conversion was done (I'm guessing 1940s-1950s) 99% of the gunsmiths never thought about .45 ACP having higher pressures than .455 ammo. I've been fooling with these large frame revolvers since the 1970s and it wasn't until I joined this forum that I learned that the US government mandated S&W 1917s be heat treated.

 

[Mlschnei]

Good morning gentlemen.
I have apparently acquired a fairly interesting little
pistol. I am saving all your comments and now
have almost enough to write a book about it .

At some point I hope to get a letter.
When I do I’ll post results here and also any
ammunition I successfully shoot through it.

Martin

 

[Hondo44]

Letters for these BSR revolvers posted on this forum typically only indicate the date shipped to Remington Arms, the procurement agent for the UK.

On the rare occasion that one of these was returned to the factory for conversion, factory work orders may be available from the S&W Historical Foundation. Your conversion is clearly not a factory conversion however.