I had same problem. https://6mmarc.com/showthread.php?tid=778
Ended up removing weight from buffer until reliable lock back. Running Superlative adj gas block with rifle +2.
I also run a 223/556 upper 20" SLR adj gas block/ rifle length and have to swap buffer/ spring to accommodate.
Philip
Ended up removing weight from buffer until reliable lock back. Running Superlative adj gas block with rifle +2.
I also run a 223/556 upper 20" SLR adj gas block/ rifle length and have to swap buffer/ spring to accommodate.
Philip