Im not sure how useful this will be but maybe. I rebarreled my UU Larue (not an OBR) from .308 to 6.5 creed. I bought the rifle +2 gas and added an SLR adjustable gas block. Also tossed in the JP Silent Captured Spring. It runs excellent, the gas block adjustability and the +2 keeps it from tearing the shit out of my brass. I run it suppressed frequently without issue, changing from unsurpassed to suppressed (or vice versa) doesn't seem to require further adjusting the gas. Its a very smooth shooter.