 The name "sabot" (pronounced in English usage) is the French word for clog (a wooden shoe traditionally worn in some European countries).Concentration of force into a smaller area was initially attained by replacing the single metal (usually steel) shot with a composite shot using two metals, a heavy core (based on tungsten) inside a lighter metal outer shell.These designs were known as armour-piercing composite rigid (APCR) by the British, high-velocity armor-piercing (HVAP) by the US, and "hartkern" (hard core) by the Germans.