But these were very common........as common as T34's in some offensives..............
http://commons.wikimedia.org/wiki/BM-13_KatyushaSome facts
http://en.wikipedia.org/wiki/Katyusha_rocket_launcherIn 44 Red army attacks would start with slavo after salvo from these things pounding the German front line. It could lauch 16 rockets per salvo and often pulled a trailer either with spare rockets or a trailer mounted launch rails. (some even pulled two such trailers 48 rockets per salvo!!!)
The most used truck for this purpose was the Studebaker.
The rs 132 rocket launched from this launcher had a range of 5 miles (just over 8 km) and a 22kg (50lb) war head.
Accurate it was not,, but a single launch would pepper an area a few hundred yards in Diameter.
Typically (in AH) launched using land mode from a spawn point it would pepper an air field (or town) with 16 x 50Lb rocket hits per salvo. (32 if the trailer option could be taken.)
Deploying would be some 30 secs
Relaoding would be a matter of a minute or so.