The fuzzy side velcro and a few coils off the ejector spring would be a start. So that the ejector, when unpinned, sits about 1/8 inch or so IIRC, above the face of the bolt.... I'd have a spare spring handy before I clipped though....just in case.
Too much gas generally shows as lifted rims on firing, IE opening the bolt before the brass shrinks.
Just a slap on the gun, nick the anodizing and ding the brass... every last AR I've had would do that if you didn't play with them a bit and soft coat the deflector.
You'll find if you trim the ejector spring too your brass falls in neater piles, and generally starts falling almost in front of you instead of way off and behind you...
Ours were tuned that if you knew where to place a cap in say sititng rapid fire, all cases would be in the cap after 10 were fired....
