I added a Riflespeed adjustable gas block to my Blackout this evening.
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This is the way. It eliminated my blowback problem where only the weakest loads were cycling without excess gas in my face or pop in my ear.
So far I’ve found that Hornady Blacks cycle fully (meaning they blow the bolt back into the open position after the last shot) on number 10, where 12 is wide open and 1 is nearly fully shut. They also cycle seemingly fine on 9, just not enough to lock the bolt open on the last shot.
For the Winchester white box ammo, the same performance happens at 6 and 5 respectively.
The Sellier and Bellot supersomics I have will fully cycle on 1. The gas blowback and pop from the breech is pretty much eliminated.
I can’t recommend this kind of finger-adjustable gas block enough if you plan on running various subsonics suppressed and also run supers once in a while. The amount of easy control and results it gives you is very tangible. Each load is now a smooth and quieter shooting experience