Bushmaster upper, Colt Bolt, LMT Bolt carrier (enhanced, non chrome)

Was shooting today, BCG locked up.

We got it out, started looking around, took the bolt out of the BC (that was more difficult than usual), looked the bolt over, it wouldn't go back into the carrier.

Looked closely, the gas ring closest to the muzzle was crimped/dented towards the bolt face. What would cause this? LMT BC w/ Colt Bolt?

How to fix? get a same company bolt/BC ?

thanks neil, appreciate the response....ttt for anyone else..

Before installing the new gas rings, do check the inside of the gas chamber section on the carrier to confirm that there are no Hi burs that may be catching/distroying the rings.

Second, when you do get the new rings, check the edges of them for burs that may be catching the start chrome plated section of the carrier, and the damage being caused when putting the B/C back together after cleaning.  The rings are stamp cut, so the top stamped side will be rounded, and the bottom section is the side that may have stamping burs. If needed, use a stone to break the sharp bur'd edge.


Lastly, the Ring (s) may have been distroyed if you had a primer blow, and a piece of it lodged into the ring section.  Having seen carrier keys and gas tube taking out by primer anvils/cups lodged in them, a piece of blown primer making it way into the bolt to do damage is not out of the norm.

dano, thank you very muchf for the detailed response, I will make sure to do all of that when I fix this.