Can over gas destroy accuracy?

[Yondering]

You need to choke the gas flowing back into your bolt carrier expansion chamber.

I personally use Bootleg Adjustable Gas carriers, which are easy to adjust through the ejection port with a flat head.

Others have been having great results with Riflespeed adjustable blocks with 12 positions.

I built 2x 6.5 Grendels with 12” CLGS barrels, one of which got a 5” Ultra and the other an Ultra 7. Both have Bootleg carriers set at fully-choked when suppressed, both run great. I’ve shot my 12” for 7 years, 6 of those suppressed with the Ultra 5.

Ejection can easily be set at 4-4:30.

FYI the Bootleg adjustable system does not choke down the gas like an adjustable gas block; it bleeds off excess pressure before it gets to the carrier's piston chamber.

I use them too, and have been since before most anyone else here was talking about them, but prefer to also use a set & forget style AGB for initial tuning of the gas system unsuppressed, and then only use the Bootleg carrier to adjust for suppressed use.

Another good option I also like is Seekins' "Select Adjustable" gas block - do the initial tuning with a set screw, then you have about 6 clicks of adjustment with a handy lever to go from unsuppressed to suppressed. Downside is it only works with certain handguard configurations unless you're willing to heavily modify them.