Allegedly,they were a part of the 1st Heavy SPG Regiment in Strašice (created in Autumn1950), where they at first formed one batallion, later it was increased to two.The regiment was disbanded in 1956 and the vehicles were transferred to army reserves. The date, when they were removed from reserves, is not known, but they most likely survived in reserve warehouses until the first half of the 70′s. Francev states that between 1966 and 1972, several vehicles were assigned to the Border Guard units (border guards were a part of the army, not police).The only real use for them was training and of course, military parades. Heavy self-propelled guns were not a popular category in the Czechoslovak army – medium self-propelled guns SD-100 (license produced SU-100 with some smaller improvements) were far more popular and remained in service for a long time(far longer than they should have due to politics – they were also widely exported and a lot of “SU-100〃 vehicles, participating in the middl