Colt 1917 headspace issue

does it happen with ammo of all manufacture?

It's possible the cylinder crane is bent, or sprung.
This is what happens when people "Bogart" a revolver by flipping the cylinder open and shut with a flick of the wrist.
These older, pre-war Colt's had softer metal than todays guns and bend easily if dropped or get slammed open and shut.

The other possibility is the chambers are dirty and need to be properly cleaned with a bronze chamber brush, or the cylinder is one of the after-market cylinders sold in the 60's as replacements and wasn't properly chambered.

It is probable that you don't need or want a different crane. You may find a used one, but keep in mind that each one was fitted to a particular revolver, and they are not supposed to interchange between guns.

If the crane barrel (the part the cylinder revolves on) is bent or sprung it can be straightened by a gunsmith who is qualified to work on these model Colt's. They're not many left, but I would start by calling the factory's customer service department.

Incidentally, I have watched factory trained & qualified 'smiths correct a sprung crane in under five minutes.

S&W armorers are issued a bar of babbit to beat crooked guns into alignment.
No doubt it is more complicated for a Colt, most things are.

Wow, that crane business seems way out. I assume the gun is chambered for .45 ACP, not reworked for something else. If so, the problem seems to be chambers too short (too little headspace). Unless there is something else wrong, why not just run a .45 ACP reamer into those chambers and take a bit off the shoulder? Possibly at one time the cylinder was replaced or a cylinder of another caliber was reworked and the chambers weren't headspaced properly.

Jim

+1
If it were a bent crane causing the cylinder to set in the frame at an odd angle?
And the cylinder is perfectly true?

All six chambers would be at the same odd angle when they turned around to the two tight spots.

It has to be two short chambers.
It is possible they all measure within .002" headspace protruding from the chambers.
But if the rear face of the cylinder is not square with the axis of rotation some of them will bind against the recoil shield.

If at all possible, I would get the stripped cylinder in a lathe, trued with a live center, and slap a dial indicator on the rear flat to see if it is square with the crane / ejector rod hole.

At any rate, I think a chamber reamer is going to be the likely thing you will need to fix it.
Not a new crane.

rc

If the crane were at an angle, the rounds would rub on the recoil shield as they come up; the chambers would all be "short" at one point in rotation. As for the rear cylinder face, it is pretty much irrelevant except when using moon clips; the .45 ACP is supported (or "headspaces on" if you prefer) the case mouth coming against the shoulder in the chamber.

I would have a gunsmith run a reamer in those chambers, or even buy a finish reamer, but if it is DIY make sure you don't take too much off. The .45 ACP is supposed to be supported by that shoulder; if it is supported by the moon clip, you can get erratic ignition and inaccuracy.

Jim