Originally Posted by
MistWolf
Straight Shooter,
The Young NM carrier body has larger the milspec dimensions so it fits in the upper with tighter clearances. The idea is to reduce play and increase in precision. According fo the guys on the National Match forum, it does nothing to help precision. The carrier is designed to float inside the upper. Less clearance means the carrier is less tolerant of residue, debris and gummed up lube.
Bolt not going into battery when hitting the bolt release is one symptom of a bad recoil spring.
When you get this sorted out, you should get 500 to 1000 rounds of trouble free shooting before experiencing empty cases getting caught in the action. I'll save you trouble and tell you now, THAT problem will be the extractor spring. The fix is to install a new spring from Colt or Sprinco.