1917 colt DA .45 question

[flydoc]

Have a question for any gunsmiths in the forum. Will a 1917 colt DA ( new service) 45LC cylinder fit and function in an original frame of a 45 ACP revolver , providing it has the correct extractor?

[gnoahhh]

It should. I will guarantee there will be a fair bit of fitting involved (hand, pawl,etc.) though. A bigger concern would be if bore/forcing cone dimensions are compatible with the .45 Colt. Go over to the Cast Bullet Association forum and ask Ed Harris about it. He did that very trick about 30 years ago and wrote it up in Gun Digest.

[Char-Gar]

I agree that it should with fitting. There will not be any bore, forcing cone problems as Colt kept the 1917 barrel specs (.452) in their New Service 45 Colts.

Ed is a good guy to ask about this and just about anything else gun related.

I can't help myself, here is my New Service 45 Colt and my 1917.

PS: Being an idle sort, with time on my hands, I tried switching out the cylinders on the two handguns below. They did not switch!

[flydoc]

Thanks gnoahh and Char-gar, I will look up the reference on Mr Harris. I figured the hand would need fitting, was hopeful I could find a 45 LC hand that I could use to replace the original, so as not to burn any bridges and to be able to alter it back to original.

[Nueces]

The reason for lack of interchangeability is that little tab on the frame at the left right below the rear face of the cylinder. Look at Char-Gar's photos. This tab keeps the cylinder from sliding off the crane when it's opened for ejection. The ACP tab is thicker, front face more forward, on account of the increased rear cylinder gap to accommodate the Auto Rim case or moon clips. A 45 Colt cylinder can have a small rebate turned into the OD of the rear face to clear this tab. That is what Harris had done.

[Outpost75]

Same mod is done to fit a .45 Colt cylinder to the M1917 S&W to clear the " frame lug", which us what S&W calls it.

[flydoc]

Now that I am looking at it, sure appears obvious. Thanks for pointing that out.

[gnoahhh]

I never knew they kept the same bore dimensions for both cartridges. Learned something new.

For how long did they do that? My .45 Colt New Service dates to 1920, and it has .454 throats, and a .452 groove diameter. I had never checked the groove diameter in the 15 years I've owned it until now, just the throat diameters which told me all I needed to know about what size to make its cast bullets. I guess I did something right as the thing shoots like a young rifle.

I threatened long ago to do a cylinder swap on another NS I had back then, when I read Ed's article. At the time I had a huge stash of gov't surplus .45ACP and no means to shoot it up. But then I fell in love with a .38-40 New Service, and away went the .45, and the project never left the dream stage.

I always strived to have at least one New Service on hand all my life. I guess it all started in 1967 when the range master at Scout camp let me shoot his Colt 1917 in exchange for doing grunt work around the range. I was smitten from that time forward. (Smart move on his part- for the cost of a few cartridges, he got to sit on his butt while I policed up the trash, emptied the garbage, and swept up spent .22 cases!)