The M55 Reising was an American submachine gun designed by Eugene Reising in 1940, entering service primarily in the United States Naval Department along side the M1928A1 Thompson. Chambering a .45 ACP cartridge like the Thompson, although with a lower magazine capacity, the M55 saw service with the Marine Corps during the early years of World War II in the Pacific Theater. The M55 was the variant of the M50 Reising equipped with a folding stock and a pistol grip, making it more compact and a full two kilograms lighter than the Thompson. It was eventually replaced by the Thompson and M1 Carbine completely, known for its unreliability (the stock folding while firing). In addition, the M55 was slightly heavier than the M1 Carbine.
The M55 Reising's first combat mission was on the island of Makin Atoll, target of the 2nd Raider Battalion. Their mission was to severely cripple the Japanese position on the island, eliminating multiple fuel and ammunition centers. Although this is the objective in the game, in reality, the attack on Makin was simply a diversionary tactic in efforts to divert attention away from Guadalcanal. Issued alongside the M1928A1 Thompson, the M55 saw service on Makin Atoll, arming Tommy Conlin, the down Naval Aviator which the Raiders rescue and numerous other Raiders. It is not seen throughout the rest of the campaign, although in real life it and the M50 was also used in small numbers throught the war in the Pacific and even in limited use in Korean War.