Probably based on the C-More Systems CMC-M1 straight pull 12ga clip feed shotgun. Close Quarters Battle Receiver (Wiki CQBR) & close quarter combat (Wiki) 7325354 Weapon aiming device, Richard P. Grauslys, Allen R. Harding, Insight Technology, Feb 5, 2008, 42/131, 42/123 - corrects...
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