US Cartridge, 57mm AP-T, M70
The M70 AP Projectile is a solid shot of hardened steel with a cavity machined into the base to receive a tracer. The ogive is continued to a point, and has a radius of 3.14 inches. A waved or knurled recess 0.79 inch wide is machined into the shot 1.01 inches above the base to receive a copper rotating band. A cannelure for receiving the crimps from the cartridge case is located 0.51 inch behind the rotating band.
The tracer charge consists of approximately 73 grains of red tracer composition in the form of 3 solid pellets and 20 grains of igniter charge in one pellet. The tracer charge is sealed into the tracer cavity with a clear celluloid cup cemented into place. The tracer burns for about 3 seconds.