Quote Originally Posted by AH64Armament View Post
The first problem was the Extractor spring plunger broke... replaced it and moved on.
Hello Mark,
Welcome to Mil Surps
Hang on, I'm sure the right 'Answer man' will come along.
In the mean time... I'll try some help.
What type of plunger was installed? Was it a USGI replacement?
Many of us have found that the commercial replacements like the Iver Johnsons sold by Numrich aren't up to par, I think fellow member Tired Retired will agree here.
Keep in mind these little plungers are a weak spot on any M1icon carbine.
Look very closely to see if the plungers flat edge is resting ON TOP of the Extractors ledge.... See Pic:


Make sure the inside rails the bolt lugs ride in are cleaned, free of burrs and lightly lubed. Same with the outer Op slide grooves and the slides notch that the right bolt lug meets. Be sure the bolt is cleaned inside and out, including that the firing pin slides freely, and the head of the Ejector on the face of the bolt pushes in and springs back out with out binding.
Chamber and feed ramp clean.
Good strong Op slide spring.


Some related links for you:

Universal M1 Carbine Question
Universal Firearms Corp.


FWIW,
Charlie-painter777