If I read the SN correctly it seems to be in the sequence of the 2nd Model MKIIs in .455. Could the cylinder have been reamed to accept 45 Colt? In this SN range I don't think the caliber was stamped on the barrel. I think I see crossed pennants and perhaps the other usually seen British acceptance stamps on the frame. Other than that it looks like one I'd like to have I can't suggest more but others will be along who can. Oh, and welcome to the Forum, a very interesting first post.
Jeff
SWCA #1457
Welcome to the Forum.
Where is the "RCMP 724" stamping? I agree that this is a 2nd Model .455. Can you post a picture of the cylinder, taken from the rear, so that we can see the chambers? All, we need a picture of the recoil plate, the area where the firing pin protrudes when fired.
The chambers have been deepened for the .45 Colt round.
no ridges in the cyl ?
You can see the front of the chambers in your las picture. The chambers of an unaltered .455 would be much closer to the rear of the cylinder.
Nice looking gun
Chammbers are smooth yes, but, I can see the step from case size to throat size about 3/8" from the barrel end of cylinder. The cylinder retains the serial number and has no shallow recesses at the chamber, so if it was originally a 455 it would have needed about .02 taken off the face of the recoil shield because the colt has a thicker rim. (I think the recoil shield does look shaved) Of course the chambers are reamed deeper on a 45 colt than on a 455. If they were reamed deeper after production it would be difficult to see if the smith did good work.
Some S&W 45 colts were made for the Canadian RCMP. I would love to have one.
there is no step in bores, in the pic it may look to be .
i "think" the ones (724) made for the RCMP were built as 45lc not modified 455s .
Sure there is, the transition from chamber to throat area is plainly visible. It's going to be a ramp, not a sharp shoulder, but the change in diameter is there.
![]()
If you have a sufficiently accurate measuring device such as calipers or pin gages, you will find that the back end of the chambers measure about .483 and the front end will measure about .459. At least that's what my rechambered .455 measures, although on mine the backside of the cylinder was faced off, as opposed to the recoil shield on yours being thinned.
The most certain way to be sure though is to get a Letter of Authenticity from Roy Jinks, S&W Historian. But I'll bet you a nickel that your gun was originally chambered in .455, not .45 Colt.
Smith & Wesson Historical Foundation - Home Page - Insuring that the rich history of Smith & Wesson will continue for generations to come
You may not see the modification but the rest of us do.
Jeff
SWCA #1457