RE: Colt M1917 Cylinder vs Colt New Service

ACESDUGOUT · October 25, 2014, 06:50 PM

Do the cylinders cross over? Can a cylinder from a New Service be used on the M1917 or visa- versa?

Jim Watson · October 25, 2014, 06:59 PM

If same caliber - .45 ACP - and with "fitting."

If different caliber, it will take more work.
I have an old article about a S&W 1917 .45 ACP-LC convertible that was a big project. Not worth it to me.

James K · October 25, 2014, 10:22 PM

Not that big a project. At one time it was very common to replace the cylinders of "cheap surplus" Model 1917's with .45 Colt cylinders. Other than replacing the cylinder (not as easy in a Colt as in an S&W, but doable), the only other change needed is to modify the cylinder stop (the part that keeps the cylinder from moving backward when open) for the longer cylinder. It is that detail that prevents having two sets of cranes and cylinders for an easy swap.

Jim

Jim Watson · October 25, 2014, 10:45 PM

The piece I have described turning a little step on the LC cylinder to clear the frame stop which was left at the size for ACP.

James K · October 26, 2014, 07:34 PM

I admit I didn't check, but I didn't think there was enough steel at that point in the cylinder to allow that much to be cut away. The conversions I have seen modified the stop, since the conversion to .45 Colt was intended to be permanent.

Jim

October 25, 2014, 06:59 PM	#2
Jim Watson Senior Member Join Date: October 25, 2001 Location: Alabama Posts: 18,545	If same caliber - .45 ACP - and with "fitting." If different caliber, it will take more work. I have an old article about a S&W 1917 .45 ACP-LC convertible that was a big project. Not worth it to me.

October 25, 2014, 10:22 PM	#3
James K Member In Memoriam Join Date: March 17, 1999 Posts: 24,383	Not that big a project. At one time it was very common to replace the cylinders of "cheap surplus" Model 1917's with .45 Colt cylinders. Other than replacing the cylinder (not as easy in a Colt as in an S&W, but doable), the only other change needed is to modify the cylinder stop (the part that keeps the cylinder from moving backward when open) for the longer cylinder. It is that detail that prevents having two sets of cranes and cylinders for an easy swap. Jim

October 25, 2014, 10:45 PM	#4
Jim Watson Senior Member Join Date: October 25, 2001 Location: Alabama Posts: 18,545	The piece I have described turning a little step on the LC cylinder to clear the frame stop which was left at the size for ACP.

October 26, 2014, 07:34 PM	#5
James K Member In Memoriam Join Date: March 17, 1999 Posts: 24,383	I admit I didn't check, but I didn't think there was enough steel at that point in the cylinder to allow that much to be cut away. The conversions I have seen modified the stop, since the conversion to .45 Colt was intended to be permanent. Jim