Originally Posted By Lester1965:
I have the Magpul MOE grip that has the spot for an extra firing pin and bolt. I have a colt 6921, 6920, and 6933. Are bolts universal? Will one bolt fit all ar's? Is BCM better than the factory colt bolt? This is one of my SHTF rifles so I want the spare bolt and firing pin to be combat hard use grade. What firing pin should I throw in?
I also have Colt models 6721 (X2), 6920, and MT6601 and I vote for Colt bolt, but other equivalent high quality brands that are high pressure tested (HPT) and magnetic particle inspected (MPI) like BCM, Daniel Defense, LMT, Rainier Arms ThunderBolt, Spike's, etc will also work.
Colt bolts and complete bolt carrier groups are also now available directly from the Colt factory, for other small Colt parts check out Brownells.