I have a few AGBs on my rifles. Mostly to increase the reliability of running them both suppressed and 'open header'. I believe a few of the AGBs I have are "bleed off" type (Superlative Arms being one) as opposed to "restriction" type.

Is it possible that the bleed off versions are creating unwanted noise when running suppressed with subsonic ammo? This would probably only be an issue for me using 300Blk as it's the only subsonic rifle ammo I have. Is there enough noise coming out of the BCG/ejection port already that it doesn't matter? Is there a way for me to test or measure this?