I shoot my 12.5", 16", and 20" 6.5 Grendel ARs suppressed with Dead Air Sandman-S. All run great with an H2 buffer (12.5" and 16" with Geissele Super 42 Spring, 20" with JP SCS H2). Fixed gas block on the 12.5", SLR Sentry adjustable gas blocks on the other two.
When initially test firing the 12.5" pistol without a suppressor the H2 buffer was a bit too much for it to cycle reliably. H1 buffer worked great without a suppressor.
When initially test firing the 12.5" pistol without a suppressor the H2 buffer was a bit too much for it to cycle reliably. H1 buffer worked great without a suppressor.