Broke an extractor

[LRRPF52]

What is your barrel length? In my experience, the O-ring is not needed on 16" barrels and longer, but was needed for 100% reliability on 12s.

When SOCOM switched to the heavier profile M4A1 barrel, there was a batch of barrels that had rough-textured/small chambers that caused Failure To Extract issues.

They also had problems with the SOPMOD KAC NT4 QD suppressor increasing the cyclic rate. This led Crane to put a band-aid on the carbines at that time, which was the Crane O-Ring around the Extractor spring and insert.

For a well-timed gas system, it isn’t necessary, and I remove them as a rule with all my builds if I see it present.

I’ve been running my 12” Grendel suppressed almost exclusively for about 4 years, and we have a duplicate of it I built for a friend who also shoots suppressed.

I used the same 12” Group Buy Faxon barrels for these builds, with Monster bolts, and Bootleg Adjustable Gas carriers.

He’s shooting with the TBAC Ultra 7 can exclusively. I’m shooting with TBAC Ultra 5.

He’s shooting 107gr SMK on 8208XBR after some initial shooting with factory 123gr ELD-M and his 123gr SMK hand loads.

I’ve shot 90gr TNT, 120gr Federal OTM, 123gr American Gunner, and 123gr ELD-M. I have a 3-4 year report to do on the 12” when I get a chance.

I’ll go double-check that I removed the O-Rings.

ETA: Checked my 12” Grendel and I did remove the O-Ring when I built it. I’ve had zero FTExtracts so far. I think I completed the build in either 2018 or 2019, no later than 2019 for sure. I’ve primarily been shooting the 12” for all of my intermediate-long range work since that time. I cheated on it twice and shot my 17.6” Lilja Grendel with the kids out in the desert, on my steel poppers at distance.