M93 HVAP
M93 HVAP ammunition is a type of round used to penetrate German armor. It became available in 1944 and proved decisive at Arracourt when M4 Shermans destroyed many Panthers.
The idea is to concentrate all the kinetic energy into the core of the projectile. The M93 used a very dense, hard, tungsten core that travelled at a high velocity or "hypervelocity". It was surrounded by aluminum.
Tungsten carbide was rare at the time and hard to obtain. Sources were from southern China, South America, and the western United States.
It was very effective at short to medium range and when it hit targets square-on. At longer ranges, it would lose some velocity and the tungsten projectile could shatter.