Instruction memorandum regarding the gun and recoil mechanism, 37-mm, M1916 (subcaliber) and subcaliber mounts.

General --References -- General information -- Summary of subcaliber mounts -- Gun and recoil mechanism, 37-mm, M1916 -- Characteristics -- Description -- Ammunition -- Adjustment, operation, and maintenance -- Bore-sighting and adjustment of mount -- Witness lines -- Operation and safety precautions -- Care and maintenance -- Description of mounts; assembly -- M1 mount for 155-mm gun, M1918 (GPF) and its modifications -- M4 mount for 155-mm howitzers, M1917A4 and M1918A3 -- M5 mount for 75-mm howitzers, M1 (pack) and M3A1 (field) -- M10 mount for 155-mm gun, M1, and 8-inch howitzer, M1 -- M12 mount for 105-mm howitzer, M2.