How many rounds per second did the Ju 87G's BK 3.7 fire?

Short answer

The Ju 87G's BK 3.7 had a rate of fire of 160 rounds per minute. Each of the two 37 mm cannons was mounted in an underwing gondola with a six-round magazine of tungsten-carbide armour-piercing rounds. Muzzle velocity was between 800 and 1,140 m/s (2,600-3,700 ft/s).

Published: November 4, 2026 · Updated: November 4, 2026 · Edited by Above Ten Thousand · Editorial policy

How many rounds per second did the Ju 87G's BK 3.7 fire?

Junkers Ju87G 2 494083 W8 A CHIV 22 08 70 edited 2RuthAS (CC BY), vía commons

Rate of fire and ballistics

The BK 3.7's rate of fire was 160 rounds per minute. Its rounds left the muzzle at between 800 and 1,140 metres per second (2,600-3,700 ft/s). The cannon was fitted to Luftwaffe aircraft such as the Junkers Ju 87 G-1 and G-2.

Two gondolas under the wings

The Ju 87's two 37 mm (1.46 in) Bordkanone BK 3.7 cannons were mounted in underwing gondolas. Each gondola carried a six-round magazine of tungsten-carbide armour-piercing rounds. These gondolas were fitted to a Ju 87 D-1, W.Nr 2552, nicknamed "Gustav the tank killer".

An idea from Rudel

Hans-Ulrich Rudel, the Stuka ace, had proposed using two 37 mm (1.46 in) Flak 18 cannons, each in its own self-contained underwing gondola, as the Bordkanone BK 3.7. The weapon could be extremely effective in the hands of a sufficiently skilled and trained ground-attack pilot, such as Rudel in his Junkers Ju 87G armed with the BK 3.7.