45 Colt US Army 1917?

[tentcamper]

What exactly do I have?

Several years back I found a Smith & Wesson 1917 at a LGS for a reasonable price. This one is chambered in 45 Colt. Barrel is marked S&W .45 on one side and I.N.A. on the other side, no markings on barrel top. The gun is pretty tight and functions properly. Looks like the cylinder was changed out at some point from 45 acp to 45 Colt.  I have not fired this although it sure looks like I could safely do so.

I have not found much online on these being adapted to 45 Colt. I'd appreciate any insight into these being converted, I presume post war. Bottom of grip is stamped US ARMY model 1917. Serials match on grip frame and cylinder

Thanks!

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[45MAN]

INTERESTING, I DO NOT HAVE ANY ANSWERS

[strawhat]

Switching the cylinder is an option. But, if they did not change the frame lug, the cylinder gets a running start at deform itself and/or the frame lug. I am not near my micrometers or calipers, but will measure and post how long an ACP cylinder is and also, how long a long Colt cylinder is.

Kevin

[blackhawk44]

Appears to refitted with rechambered .455 cylinder from WW1 British contract surplus in 1950's. Likely not factory available part since there were only about 750 Colt chambered original 2nd model hand ejectors from 1914 to 1940.

[strawhat]

I just reread the opening post, the serial on the butt matches the serial on the cylinder. So, it is either the original cylinder or someone had a set of stamps.

The original cylinder could be rechambered but it would have to be done in such a way that the cartridge would headspace on the case mouth. Which means a short chamber that is tight at the bullet end. A normal chamber cut, to headspace on the rim, would leave the cartridge too far from the firing pin.

INA barrels were made in Brazil for the Model 1917s they purchased before and after WW II.

Kevin

[strawhat]

Can you post some images of the cylinder with the 45 long Colt cartridge in place? Cylinder open and closed would be nice.

Will it still chamber the ACP round?

Kevin

[tentcamper]

Apr 28, 2024 6:46:41 GMT -5 strawhat said:

Can you post some images of the cylinder with the 45 long Colt cartridge in place? Cylinder open and closed would be nice.

Will it still chamber the ACP round?
Pics attached. The 45 acp will not chamber, it only slides forward and stops on the chamber cut. The cylinder only measures 1.538" (compared to a ruger Vaquero cylinder measuring 1.711") and the pictured 200 grain 45 Colt loads take up all the lengthwise room i the chamber. (Not sure a 255 grain bullet would fit).Pics as requested. 45 Colt with chamber open and closed and 45 acp (acp rounds fall into chamber and stop at chamber cut.
I am guessing this was reamed out and converted to a 45 Colt.

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[tentcamper]

45 acp rounds in 1917.

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[strawhat]

Thank you.

The fact that the 45 long Colts chamber deep enough to headspace on the rim makes me wonder how the expected the firing pin to reach the primer? The original cylinder was set up to headspace on the chamber mouth but they needed space for the clip, so the chamber was cut short enough for the thickness of the clip and the rim would put the primer in the firing zone of the hammer.

The cylinder still retains the serial number so there is a lot of real estate for the firing pin to cover. Perhaps a longer firing pin was installed? But then it would pierce the ACP primers?

An interesting revolver. One I would like to handle and observe.

Kevin

[45MAN]

IN HIS OP tentcamper SAID HE HAD YET TO FIRE THE GUN SO WE DO NOT KNOW IF IT WILL FUNCTION AS A 45 COLT? tentcamper: TRY AND SEE PLEASE, THEN REPORT BACK.

[tentcamper]

Apr 28, 2024 19:15:16 GMT -5 strawhat said:

Thank you.

The fact that the 45 long Colts chamber deep enough to headspace on the rim makes me wonder how the expected the firing pin to reach the primer? The original cylinder was set up to headspace on the chamber mouth but they needed space for the clip, so the chamber was cut short enough for the thickness of the clip and the rim would put the primer in the firing zone of the hammer.

The cylinder still retains the serial number so there is a lot of real estate for the firing pin to cover. Perhaps a longer firing pin was installed? But then it would pierce the ACP primers?

An interesting revolver. One I would like to handle and observe.

Kevin

It LOOKS like the FP will contact the primer. Only one way to find out. I'll keep you posted.

It is a neat old gun. I have several other older guns but this one is my favorite.

[45MAN]

DO NOT KNOW WHY OR HOW IT WORKS BUT bigbrowndog SAYS HE LOADED UP SOME SHOT SHELLS USING 45 COLT BRASS FOR USE IN A BRAZILIAN S&W 45 ACP AND THAT THEY WORK FINE.

[bigbrowndog]

Yep, they go bang everytime,……so far. Technically they are shortened 460sw cases, cut full cylinder length.

Trapr

[bradshaw]

Was handed, roughly a lifetime ago, a Colt Model 1917 .45 ACP, its chambers reamed straight through for cut-off .30-06 shells in half moon clips. Lands reamed out the barrel, a sixshooter shotgun. Highly illegal even back then, though who knows whether the deed was done before the Federal Firearms Act of 1934 ostensibly enacted to curb gangsters. Never occurred to me to ask who made dies to load sawed off .30-06 shotshells. Indeed, back then I encountered more World War I Colt than Smith & Wesson .45 ACP’s.
David Bradshaw

[45MAN]

DAVID: AT LEAST THE EARLY COLT 1917's HAD CHAMBERS DRILLED STRAIGHT THRU (NO SHOULDER FOR A CASE TO HEADSPACE ON), COULD'a BEEN WHAT YOU HAD IN HAND. THE "SMOOTH BORE" WAS PROBABLY A POST MANUFACTURE "CUSTOM" TOUCH.