HEVI-Shot’s HEVI-Hammer leads to tighter patterns more knockdown power, and flat-out increases your chance of success in the field. It features 15% high-density bismuth, layered over 85% steel pellets. The Bismuth layer is the same shot size as the steel. That small but mighty leading edge of bismuth packs nearly 50% more knockdown power than the steel layer at 40 yards.