According to the U.S. M1 Carbine Serial Numbers production chart, this I.B.M. (International Business Machine Corp.) U.S. Carbine was produced in 1944. MARKINGS: "I.B.M. CORP./ 3956990" on the rear receiver, "I.B.M. CORP." on the top of the barrel, Crossed-Cannons Ordnance inspection stamp on the right side of the stock, Flaming Bomb on the sling well (other sling well markings not legible), "P" proofed under the grip, "U" on the magazine and "U.S. CARBINE/ CAL. 30 M1" on the front receiver. SPECS: 18" Barrel, adjustable rear peep sight, front band sight with ears and green canvas sling. CONDITION: This gun is in nice condition with light wear, has an excellent sharp/ clean bore and appears to be in good working order. HISTORY: In 1941, with the U.S. being pulled into one of the greatest conflicts in world history, many U.S. manufacturers were tasked to switch production to support the war effort. Manufacturers tasked with M1 Carbine parts & production included - Inland Manufacturing (Division Of GM), Saginaw Steering Gear (Division Of GM), Quality Hardware & Machine Co., International Business Machines Corp (IBM), Rock-Ola Co., Standard Products, National Postal Meter, Winchester and others. The M1 carbine is a lightweight semi-automatic rifle that was a standard firearm for the U.S. military during World War II and used primarily by Airborne Divisions. FREE SHIPPING & NO PROCESSING FEES.