Inert 20mm Vulcan M55A3 Target Practice Round

Unfired case 20mm M55A3 Target Practice (TP) round (20x102mm), which measures approximately 6.5 inches in total length. The casing was drilled and there is no powder or firing cap. Markings: M55A3: The military designation for a 20x102mm target practice projectile with a hollow, inert aluminum nose, used in the M61 Vulcan and similar cannons. PBM: The manufacturer code for Pembroke Machine Company in Pembroke, North Carolina. 88B: The date code indicating it was manufactured in February 1988. 6.5 Inch: The approximate length of the full round (projectile combined with the shell casing).