Upper assembly includes:
- Inspection of all appropriate components (headspacing of barrel, feed ramp alignment, gauging of gas port)
- All hardware torqued to mil-spec with appropriate Aeroshell 33ms/Permatex 243 on all critical components.
- Roll pins seated to appropriate depth
- Barrel nut timed/torqued to manufacturer’s specification
- Dimpling of barrel for maximum set screw depth (centered over gas port)
- Muzzle device timed at 1200 position with appropriate crush washer/shims
- Gas tube provided per assembly service