"LNN" February 1944 date code on the left breech area of the matching numbered barrel. This rare shotgun was designed for use by the U.S. Army Air Corps during World War II. It was intended to be mounted in a firing fixture that simulated the door and turret mounts of World War II bombers and was to teach the proper "lead" for aerial gunnery. The receiver has four large threaded holes that attached the shotgun in an aerial gunnery fixture. The receiver is marked with flaming bomb proof, U.S. and military finish and so is the barrel. It is complete with the original Cutts compensator on the barrel. With a single nickel bead sight and 2 3/4 inch chamber. The barrel is also without choke markings which is correct. Length of pull is 13 7/8 inches.