High Quality Content by WIKIPEDIA articles! The D-30, or 122-mm howitzer D-30 (GRAU index 2A18), is a Soviet howitzer that first entered service in the 1960s. It is a robust piece that focuses on the essential features of a towed field gun suitable for all conditions. The D-30 has a maximum range of 15.4 kilometers, or over 21 km using RAP ammunition.