The gun can fire APFSDS-T (BM-421 Sg), shaped charge (BK-412R and BK-5M), high explosive (OF-412), armour piercing with tracer (ballistic-capped BR-412B and BR-412D) and target practice (PBR-412 and PBR-421B) rounds. There was also an APFSDS round that is no longer in production. In order to increase the firepower of the TR-85 tank, the BM-421 Sg round (known internationally as the M309 cartridge) was developed in cooperation with Israel as part of the modernization program started in 1996. Made by Aeroteh SA from Bucharest and marketed by ROMARM SA, the BM-421 Sg projectile can penetrate 444 mm of RHAe at 90° at 500 meters, 425 mm at 1000 meters and 328 mm at 4000 meters.