The Northrop P-61 Black Widow had a gun mounted that was designed by whom?
M2 Browning The M2 Machine Gun or Browning .50 Caliber Machine Gun is a heavy machine gun designed toward the end of World War I by John Browning. Its design is similar to Browning's earlier M1919 Browning machine gun, which was chambered for the .30-06 cartridge. The M2 uses the much larger and much more powerful .50 BMG cartridge, which was developed alongside and takes its name from the gun itself (BMG standing for "Browning Machine Gun"). It has been referred to as "Ma Deuce", in reference to its M2 nomenclature. The design has had many specific designations; the official designation for the current infantry type is Browning Machine Gun, Cal. .50, M2, HB, Flexible. It is effective against infantry, unarmored or lightly armored vehicles and boats, light fortifications and low-flying aircraft. The M2 has been produced longer than any other machine gun.
SU-122-44 The SU-122-44 was a Soviet self-propelled gun (SPG) prototype. The classification "44" stands for the T-44 tank chassis, which this SPG utilized. It was designed in early 1944 with a 122 mm D-25-44S gun, with its fighting compartment situated at the front of the hull. The front had a sloped 90 mm armor plate, with an inclination of 27 degrees. The side armor plating was 75 mm thick, and the rear was 45 mm thick. The design was found to be too heavy and too large for its intended use. Its competitor, the SU-100-M-2, proved a superior design, and on 7 March 1945 all work on the SU-122-44 was terminated.