Navy's largest machine gun was the Bofars designed 40mm Mk3, an
automatic, rapid firing anti-aircraft gun, capable of
delivering 160 rounds per minute at a maximum range of 2,800
yards - although its most effective range depended upon the
actual type of ammunition used.
single 40mm was air cooled and manually loaded, aimed and
fired, both the twin and quad (double and quadruple
barreled) guns were water cooled and was capable of firing
by either manual, local power or by director power fire
control which were normally found on surface combatants of
destroyer escort size or larger.
depended upon the gun - The single 40mm had a crew of four,
the twin had seven and the typical quad gunnery crew
consisted of eleven. Ammunition was fed into the loader by
hand in clips of four rounds. The fully automatic gun
mechanism operated through the recoil.
40mm had two loaders and no Gun Captain. The Twin and Quad
40 crews both had Gun Captains with four and eight loaders