Germany SturmPanzer IV early Sd. Kfz.166 "Brummbar"

The Sturmpanzer was a development of the Panzer IV tank designed to provide a vehicle offering direct infantry fire support, especially in urban areas. It used a Panzer IV chassis with the upper hull and turret replaced by a new casemate-style armoured superstructure housing a new gun, the 15-centimetre (5.9 in) Sturmhaubitze (StuH) 43 L/12 developed by Skoda. It fired the same shells as the 15 cm sIG 33 heavy infantry gun. Thirty-eight rounds, with separate propellant cartridges, could be carried. An MG 34 machine gun was carried that could be fastened to the open gunner's hatch, much like the arrangement on the Sturmgeschütz III Ausf. G. Early vehicles carried an MP 40 sub-machine gun inside, which could be fired through firing ports in the side of the superstructure. Early vehicles were too heavy for the chassis, which led to frequent breakdowns of the suspension and transmission. In October 1943, it was decided that the StuH 43 gun needed to be redesigned to reduce its weight. A new version, some 800 kilograms (1,800 lb) lighter than the StuH 43, was built as the StuH 43/1. Some of the weight was saved by reducing the armour on the gun mount itself. This gun was used from the third production series onwards. Zimmerit coating was applied to all vehicles until September 1946