BCM bolt assy and the donut question?

mattjmcd · #1 12-09-09, 12:01

Does anybody run their bolt with the black rubber o-ring shipped with this bolt assembly? I have heard some mixed messages regarding the advisability of using it. What say you?

ForTehNguyen · #2 12-09-09, 12:29

donut was designed to add spring tension for carbines to slow its extraction down a little. I dont thing my BCGs have it and I haven't had any problems, I have carbines and midlengths.

mattjmcd · #3 12-09-09, 12:37

Quote:

Originally Posted by ForTehNguyen

donut was designed to add spring tension for carbines to slow its extraction down a little. I dont thing my BCGs have it and I haven't had any problems, I have carbines and midlengths.

That's more or less what I am hearing the most.

BTW- your handle cracks me up! FTN!

TomMcC · #4 12-09-09, 12:48

Actually the donut is to increase extractor tension, it does not slow down extraction. Things like heavier buffers, more rifle like gas pressure slow down the extraction process. Carbines can be over-gassed, this can increase BCG velocity causing extraction to begin before gas pressure drops sufficiently in the barrel.

ForTehNguyen · #5 12-09-09, 13:16

thanks someone finally noticed

I ran the carby through classes, shot about 600 rounds total through two different dates, no malfunctions of any kind. Mine doesnt have the donut

SWATcop556 · #6 12-09-09, 15:58

I use the O-ring in my SBR's but I leave it out of my midlengths.