Ordnance provision system. [Ordnance catalog (ordnance provision system): Group C, Gun, 4.5-in., M1, and carriage, gun, 4.5-in., M1, major items, maintenance parts and equipment required for maintenance of gun, 4.5-in., M1, carriage, gun, 4.5-in., M1, and mechanism, recoil, 4.5-in., gun, M5, addendum; Jan. 21, 1943.