So, for my soon to be 12" Grrr future suppressed...

[Sticks]

I have a SLR sentry 7 clamp gas block on a Faxon 12" and all I can say is it works as expected. But you need to watch the inside Id of the rail you use as mine is touching the rail in three spots. Both clamp screws and the leef spring screw. Kinda bummed as it's being used under a SLR rail and it's not very compatible even though they say it is. I think it's really affecting my accuracy. I'm getting 6 to 7 moa with wolf at 50 yards. Not good!

Wolf sucks as a rule. 2 MOA out of a 18" cut rifle, not 5r - which adds insult to injury let alone only 12" to spin an undersized pill (.2619").