Faxon AR-15 5.56 NATO Threaded Barrel 16in Gov't/Socom Mid-Length 1-8 Twist 1/2-28 4150 Nitride w/ Pinned Gas Block 15A58M16NSQ-APGB. .. look no further. Pinning your gas block in addition to the use of set screws gives the user the extra piece of...