Original U.S. WWII Sperry Aircraft Gunsight K-13 Compensating Sight 81mm Mortar Darling stated that the re-inforced

Darling stated that the re-inforced collar on the 2nd ramrod guide is an invention of John Pratt

is revealed

whose distinguished career in the French Revolutionary and Napoleonic Wars was a catalogue of the highest and lowest points of the Navy during the conflict

Fully Cleaned and Ready to display and research

Original U.S. WWII Sperry Aircraft Gunsight K-13 Compensating Sight 81mm Mortar Darling stated that the re-inforcedOriginal Item: Only One Available. The K 13 Compensating Gunsight, made by Sperry, is an electrically powered gunsight designed to compensate for altitude and airspeed. Typically mounted on the rear housing of a . 50 caliber machine gun from a side waist gunner position in the aircraft. Used in Boeing B 17 Flying Fortress and Consolidated B 24 Liberator bombers during WW2. It was a late war innovation that used the aircraft altitude and speed with the