MIL-S-63348A (AMENDMENT 3), MILITARY SPECIFICATION: SUBMACHINE GUN, 5.56MM, PORT FIRING, M231 (03 AUG 1983) [NO S/S DOCUMENT]., This Amendment forms a part of Military Specification MIL-S-63348A(AR), dated 20 Auqust 1981, and is approved foruse by the U.S. Army Armament; Munitions and ChemicalCommand, and is available for use by all Department andAgencies of the Department of Defense.