Captured by Germans BM-8-24 multiple rocket launcher based on T-60 hull. Guards Mortar Battalions of Tank Corps were equipped with such vehicles. BM-13 based on STZ-5 NATI prime-mover chassis
Not just Sherman Calliope (about two zillion variants), there was the Guards Armoured as well with "Tulip" - a bog-standard Sherman with an aircraft rocket rail fastened to the turret side mounting a total of 2 x 60lb rockets. David Fletcher (Universal Tank IIRC) says that anything was liable to be hit, from 400 to 1200 yards (I think it was), but accuracy was poor :-? I still wouldn't have liked to be in the firing line.
Ungided ground to ground missiles at the time were notoriously inaccurate. Sovets were first to solve this by saturating area that was beeing targeted. If you fire 24 rockets per wheicle and you have 20+ wheicles you are bound to hit something. As one german veteran said they were hated as they could fry (his words) the entire battalion in few seconds.
All rockets of that period were iffy. Air-ground, ground-ground and air-air. In fact the Russian RS-series (82/ 132 and a couple of other sizes I think) were developed originally for air-air and were so useless they were switched to ground attack weapons. Yeah saturation is one way to go, lots of little ones, but 2 x 250 kg is another way - a small number of vey large ones. I would imagine (haven't got the formula to hand for HE burst/ destruction radii) that a 250 kg weapon covers a fairly large area, especially if it has a fragmentation effect as well as pure blast.
That is about the meanest looking tank I've seen. You can't leave us hanging like this. Did this thing actually see any combat? Was it part of the "funnies"?
Wasn't the 105 mm gun on this tank a dummy ? I do believe it had two .50 cal guns in ball mounts near the turret centre Aglooka