Locking bolt questions

[faraim]

My 2" m15 is quite loose where the extractor rod meets it's locking bolt. The pin that extends out of the front of the barrel underlug is out farther than on any of my other K frames. Also the locking bolt extends to the rear quite a bit less. Does anyone have ideas on how to fix this?

 

[snubbiefan]

Was it ever "normal", or did you obtain it in this condition? Could be several things, from a weak or broken center-pin or bolt spring to something blocking the action of either. If it was obtained this way as-is...could have the wrong parts installed. From what you describe...it appears to be something jamming the bolt spring or bolt. The bolt-latch out front has a spring that pushes against the center-pin and it's spring, which both push against a spring to overcome force in a 180-degree direction from the thumb-latch (bolt).

Does the gun carry-up (latch) okay? Does the ejector stroke on the rod feel normal, or is it sticky or jammed? Can you freely work the thumb-latch through it's full range with the cylinder open? Press the center-pin with your thumb with the cylinder open and see how the resistance compares to one of your other models. If it feels much softer, that would take you in the direction of a problematic center-pin component. The latch out front needs to be pushed by hand/finger also to see if it's spring feels firm. The front latch and center-pin springs push against the bolt-latch spring. One end of this system is too weak, too strong, or jammed for some reason.

 

[faraim]

Thanks for your reply. I have compared it to my other K frames and it appears that the locking bolt just barely enters the front of the extractor rod. I plan on removing it and cleaning the recess in the underlug. If that doesn't work I will replace the parts. There is a bit of a hitch when opening the cylinder. It seems the centerpin is a few millimeters short, or perhaps the locking bolt tip is slipping between the centerpin and the inside wall of the extractor rod. After a cleaning the lock-up is quite a bit better. it's amazing how much gunk I got out of the nooks and crannies.

 

[snubbiefan]

Just think all this out. The spring in the front bolt pushes against the center pin, which has it's own spring inside the cylinder assembly that pushes the center-pin back thru the center of the extractor into the bolt-hole in the recoil shield. The main bolt has a spring that forces it in the opposite direction against the center-pin. Could be some crud somewhere in this spring "system". If you have had it a while and it just developed the problem....likely just crud somewhere along the line. If it's always been this way....who knows what length center-pin is in there.They often have to be trimmed-to-fit and won't necessarily interchange from one gun to another. The front-bolt is mostly there to lock the ejector rod in place and once closed....has little to do with pressing against the center-pin. If it protrudes with the gun in lock-up....something in the center-pin, spring, or locking-bolt system is amiss.