3.7 Cm Flak 18/36/37/43 - Flak 43

Flak 43

The new 3.7 cm Flak 43 was a dramatic improvement over the older models. A new gas-operated breech improved the practical firing rate to 150 RPM, while at the same time dropping in weight to 1,250 kg (2,800 lb) in combat, and mere 2,000 kg (4,400 lb) in transport. The barrel was shortened to 89 calibers. It was also produced in a twin-gun mount, the 3.7 cm Flakzwilling 43, although this version was considered somewhat unwieldy and top-heavy.

The Flak 37 could be found in some numbers mounted to the ubiquitous Sd.Kfz. 7 or later the schwere Wehrmachtschlepper (sWS), but the newer Flak 43 was almost always used in a mobile mounting. Most famous of these were the converted Panzer IVs, first the "interim" Möbelwagen, and later the Ostwind, which was considered particularly deadly.

Compared to its closest Allied counterpart, the 40 mm Bofors L/60, the Flak 43 had double the rate of fire and was both notably lighter & more compact; to the Bofors credit it was a slightly more powerful weapon (with greater range, ceiling, and a shorter projectile flight time) that fired a more destructive shell. Large-scale production did not start until 1944 and about 7,216 were produced by end of the war (Zwillings included, each counted as two guns).