3.1.2 Service Rifle – U.S. Rifle, Caliber 5.56 mm M16 series as issued by the U.S.Armed Forces, or the same type and caliber of commercially procured rifle, without bipod or grenade launcher, having not less than a 4 ½ pound trigger pull, with a standard-type stock, pistol grip, hanguard, and leather or web sling. The rifle must be so modified as to be incapable of automatic fire without removing, replacing, or altering parts. In all courses of fire and in all positions the standard 20-round or 30-round box magazine or a reduced capacity magazine of the same external dimensions will be attached. The gas system must be fully operational. External alterations to the barrel, upper and lower receivers, stock, handguard, or pistol grip will not be allowed, except that a device may be attached to prevent selector lever movement to the auto position. The front and rear sights must be the standard design. The rear sight aperture and front sight width may vary in dimensions to suit the shooter. The rear sight aperture may be hooded. Versions or adaptations of the M16 type rifle consisting of external modifications or alterations, will be shot as an NRA Match Rifle, except as allowed in Rule 3.1.3. The trigger weight of these versions of adaptations will not be less than 4 1/2 pounds, except as noted in Rule 3.3.1. A case deflector (DVC-T-30 or commercial equivalent) is allowed.
