View Full Version : Colt New Service Cylinder dimensions/clearances

02-24-2010, 6:33 PM
I'm trying to determine whether or not my Colt New Service has had the cylinder shaved or not. When I put in 45 acp in half moon clips they rub the receiver. Does anyone have the dimensions for the cylinder and or the headspace clearance I don't want to put anything through this thing until I'm sure! Thanks

02-24-2010, 8:37 PM
Shaved how? Do the edges of the clips rub the frame, or do the cases rub the frame?

02-25-2010, 7:57 AM
The rub marks are wider than the cartridge base! This means that the clips themselves are rubbing.

02-25-2010, 9:40 PM
So the rub marks are on the recoil shield? The clips do not touch anything but the cartriges and the cylinder.

02-26-2010, 12:04 AM
If you do find out what the problem is please post it here.
I have the same problem with my Colt 1917.
.45 ACP load and fire with no problems.
When in half moon or full moon clips, the cartridge bases rub on the recoil shield.
.45 Auto Rim load and fire without the drag.

02-26-2010, 8:01 AM
If you use cases fired in an auto, some of them will be dinged or bent where they index off the clip. This will decrease headspace and will induce rubbing the recoil shield.

Do they rub with new brass? Maybe your clips are a bit too thick. There is a guy who makes custom, thin clips.

02-26-2010, 12:08 PM
New or resized brass, doesn't matter.
I have tried half moon clips that were with the gun when I got it from my dad's uncle. He carried it as a machine gunner in WWI. They don't work.
I have tried other surplus clips from multiple sources with no luck.
So I picked up a couple thousand .45 Auto Rim cases and reload those to .45 ACP specs.
But it is a puzzlement why the moon clips don't work with this gun.

02-26-2010, 8:31 PM
Maybe you have one that is very tightly headspaced, or maybe your clips are bent.