View Full Version : M1a problems - need help

March 21, 2011, 11:23 AM
Have a friend's rifle in the shop, keeps blowing the roller off the bolt. Bolt just back from SA and the roller blew off again after about 14 rounds of NATO spec ammo. Any thoughts? Suggestions of where to look first? Thanks!

March 21, 2011, 03:53 PM
I only own one of these, so I can only suggest where I would check if I had the problem. Look to be sure the barrel is timed on the receiver correctly so the op-rod is coming straight back and is not shoving the roller at an angle. Check that the op-rod guide isn't worn excessively. If you can, swap in the gas system from another gun to try it. That might help isolate the problem. Kuhnhausen has pretty good detail on op-rod fit, and you might check there for tips.

Walt Kuleck sometimes posts on this forum and he may well have other suggestions.

March 21, 2011, 03:54 PM
Ask you question here

April 3, 2011, 10:58 PM
Buy a new bolt and confirm that the headspace is unchanged. If the roller comes off the bolt, you can't really re-install it and expect it to stay unless you replace the lock ring which is inside the roller.

- Ivan.

James K
April 4, 2011, 02:35 PM
I am not sure what you mean by "blowing the roller off". Is there gas escape involved or is the roller just coming off and you are being a bit dramatic?


April 10, 2011, 05:04 PM
By my understanding, the roller on the bolt was not removable except by grinding it off. It is pretty hard steel and you can't get to the retaining ring once it is installed. If it came off the bolt, the chance are pretty good that the bolt was damaged as a result. Get another bolt and roller or just a roller / retaining ring if you can be SURE that the bolt has not been damaged. Without seeing it, my guess is that you need another bolt.

- Ivan.