Help: under gassed or over gassed

[knitepoet]

It worked

To begin with I ran an A5 system H buffer had zero issues cycling factory hornady 123sst

You removed a part

I read where the oring under extractor was not a good thing so I removed it.

Then is stopped working

Yesterday I ran across some factory 90gr nosler varmageddon loads they would not cycle at all.

First off, I'm curious where you read/heard that the extractor o-ring was a "bad" thing? And secondly, why you didn't replace it when a previously working upper quit working?

Doesn't sound like a gassing issue to me in the least. You've greatly reduced the tension the extractor has on the case head and now a "normally" gassed load is jumping the "rim"
The loads that function, but don't lock back aren't accelerating the BCG enough for the extractor to jump out of the groove.

Something tells me that replacing the o-ring will fix most of your problems


ETA, for the record, MOST factory barreled ARs, regardless of the caliber, are over gassed, so they'll still work with some of the weaker factory loads. With my "cans" I've gone, ALMOST exclusives with adjustable gas blocks, to help with the increased back-pressure related to running a silencer