Ordnance provision system. Ordnance catalog (ordnance provision system): Group P, Materiel, 3-in., antiaircraft gun, M2A2, major items, maintenance parts and equipment required for maintenance of gun. A. A., 3-in., M2. mechanism, recoil, A. A., 3-in., M2, and mount, gnn, 3-in., M2A2. addendum; Dec. 24, 1942.