SU-122 SPG, 1446th Self-Propelled Artillery Regiment, 5th Guards Tank Army. Efforts to field an SU mounting a 122mm M-30 howitzer on an armored chassis began in April 1942, with experimentation placing the weapon on captured German StuGs and PzKpfw III hulls. Concerns that there would not be enough captured vehicles to guarantee spare parts led to designs placing the gun on a modified T-34 chassis. A total of 638 were manufactured before production concluded in November 1943. The howitzer was fully enclosed behind sloped 45mm armor, but the gun had a limited traverse. The SU-122 entered combat in early 1943, and demonstrated an excellent capability against enemy fortifications, and although its anti-armor performance was limited, it could damage even heavy German tanks at close range through the concussive impact of its large shells. The SU-122s would typically advance 200–600m behind attacking infantry or tanks to lend fire support. The pictured SU-122 was in one of the early SU mixed regiments organized with three batteries of SU-122s and two batteries of SU-76s, giving a final strength of ten of the light and 11 of the medium SPGs. By the summer of 1943, it was clear that the mixed organization led to maintenance and tactical complications, and most SU regiments were soon organized in light (SU-76), medium (SU-122), or heavy (SU-152) configurations. The 1446th lost three SU-76 and eight SU-122 SPGs during the Prokhorovka engagement.