I want to document a repair I made to my M15-4. I doubt the problem I encountered was a unique problem. ie It will happen again to somebody, or It has already happened.
Anyway. My trusty, nearly new to me M15-4 suddenly locked up. The cylinder wouldn't turn in single or double action, nor could I open the cylinder. It was also loaded. ****.
With some effort, I got the cylinder opened and unloaded it. I removed the cylinder and crane. I re-installed just the crane and felt no binding in its movement. I put the cylinder and crane back together and slowly closed the cylinder. It was binding between the recoil shield and the "bearing surface" at the back of the cylinder. I don't know what you call where the hand engages to rotate the cylinder.
It was like the crane all of a sudden got longer. The gun was clean, but I checked for any fouling under the extractor. NONE. I'm no smith, so I boxed the unit up to send back to the mother ship. I left the cylinder partially opened.
After lunch, I had a thought. It's a rare occurance, but it does happen. I took the cylinder back out of the gun. I got my trusty can of brake cleaner out and sprayed a jet stream into the core of the cylinder where the crane fits.
Out came a 1/4" long sliver of bronze brush bristle that was mashed nearly flat. Holy ****! That sliver is what held the cylinder in a bind.
I've only shot about 150 rounds out of it. The gun never did have a smooth action, but I bought it as a beater or kit gun. Now all of a sudden, the gun feels like new. I know, because I also have a new 15-4.
I'll bet you the pevious owner traded the gun, because the action sucked due to that sliver of bronze brush fouling the works. In the end, Lucky me.
peace