Sturmhaubitze 42, Sd.Kfz 142/2 Mid-Production

In 1942, a variant of the StuG III Ausf.F was designed with a 105 mm (4.1 in) howitzer instead of the 7.5 cm StuK 40 L/43 cannon. These new vehicles, designated StuH 42 (Sturmhaubitze 42, Sd.Kfz 142/2), were designed to provide infantry support with the increased number of StuG III Ausf F/8 and Ausf Gs being used in the anti-tank role.

The StuH 42 mounted a variant of the 10.5 cm leFH 18 howitzer, modified to be electrically fired and fitted with a muzzle brake. Later models were built from StuG III Ausf. G chassis as well as StuG III Ausf. F and Ausf. F/8 chassis. The muzzle brake was often omitted due to the scarcity of resources later in the war. 1,211 StuH 42 were produced from October 1942 to 1945.

The early models got the old boxy gun mantlet armor without a machinegun and the machinegun behind the classic shield which had to be operated from the outside. Late models were fitted with the Topfblende (pot mantlet) (often called Saukopf (Pig's head)) gun mantlet without coaxial mount. This cast mantlet with organic shape was more effective at deflecting shots than the original boxy mantlet armor of varying thickness between 45 mm and 50 mm. Lack of large castings meant that boxy mantlet was also produced until the very end.

Coaxial machine gun was added first to boxy mantlets and then to cast Topfblende, in the middle of "Topfblende" mantlet production. With an addition of coaxial, all StuGs carried two MG 42 machine guns from fall of 1944. Later, the Topfblende mantels are be produced without machine gun opening so there are two verions of the late models. The machine gun on the roof, could now be operated via inside. Also a smaller armor plate was provided for the protection of the weapon.