Repairing the Crane of an old Colt New Service Revolver

An older Colt New Service revolver had some problems with the cylinder closing properly. The owner had obviously seen too many Hollywood movies where a person does the reload and with a quick flick of the wrist slams the cylinder shut. This ends up bending the crane and throws the cylinder out of alignment. The cylinder won’t lock up, and in some cases won’t even close.

Kuhnhausen’s Colt manual

A repair manual written by Jerry Kuhnhausen covers such a repair in detail. What he doesn’t explain is where to get the tool from to do the job.

Removing the cylinder

If you’re not already familiar with operating machine shop equipment, I have no way of teaching you here on these pages. It’s a skill that needs to be learned in a hands on environment.

Disassembled crane

First things first…. Disassemble the crane from the cylinder. I made my own tools to do this. I don’t have measurements off the top of my head, and this ain’t Gunsmithing 101. A gun crank often has to make his own tools, and I can’t teach this in one short blog.

making the tool

Making the tool

I approximate Jerry’s tool shown in the manual. The measurements come from the end of the crane itself and the hole in the frame the crane fits into.

How the tool fits the crane

The gap shows crane misalignment

Here you can see the gap showing the direction you need to bend the crane back into to get it to fit the hole.

Delrin wedge

I use a Delrin wedge driven by a light shop mallet to move the cylinder crane in the direction I want it to go. Light taps are all that’s needed. You’re not going to gorilla force it into place as you could bend or break the part. Remember that this is a hollow steel tube.

Good alignment

With the cylinder crane aligned, the tool drops into the hole in the frame pretty easily with no force needed.

Repaired pistol with another

Reassemble the pistol and check the rotation of the cylinder. As always — each gun gets test fired in the back of the shop before returning to a customer. Any dragging of the chambers, or any early or late lock up could indicate a timing issue and you need to pay attention to cylinder stop bolt and the hand (or pawl) that advances the cylinder to the next chamber.