I haven't shot 6.8 full auto yet. I have toget with my class III dealer friend.. now that I have mags, we can get organized.
I shot this a bunch with the F/H instead of the brake. Recoil didn't seem like it was way more. Somewhat more, yes. It still seemed about the same as a 16" 5.56 AR with a plain muzzle shooting hot Q3131A.
-z