the gun fired separate loading, cased charge ammunition, with one of four possible propellant charges - the full, no. 1, no. 2 and no. 3 (the smallest). in addition to 122 mm gun shells, the a-19 could fire 122 mm howitzer shells; however because of lesser durability of those shells they could not be used with full charge; use of steely iron howitzer shells o-460a and o-462a was prohibited.