Invader, there is no entirely different discussion ;). The T-80 uses a spool shaped steel sabot with tungsten core, BM-42, while M1a2, correct, uses a traditionally shaped entirely DU M829A3 sabot. The BM-42 is a well designed round, but the problem with it simply goes too fast, meaning it works well against thin armor and somewhat thick armor at a 90 degree angle, but even against thick, slightly sloped armor, performance drops dramatically. Also, if the tank is moving, with the stabilization system active, the loader can have a tough time loading the gun, because the gun is elevating constantly to stay stabilized in relation to the earth. Fortunately, the designers foresaw this, and the loader has a switch he can activate that returns the gun, not the sight, to 0 degrees elevation for easy loading, however, the switch is not activated under normal circumstances.