M1A1 fires a APFSDS-T discarding sabot "anti-tank" shell, with the
"sabots" seen peeling away shortly after the 120mm shell leaves the barrel. The
smaller, 12 pound, 40mm penetrator thus travels at a higher speed (up to
5,000 feet per second), and can penetrate more armor when it hits an enemy tank.
The high speed round hits its target with force equal to an eleven ton truck
hitting something at a speed of 112 kilometers an hour.