Hevi-X is a tungsten-based waterfowl load and compared to steel shotshells with the same shot size, Hevi-X gives you 40% more knockdown power at 40 yards and 50% more knock down power at 60 yards. It lets you shoot 2 shot sizes smaller than you would shoot with a steel shotshell, and get 25% more pellets on target, higher down range velocity, and more consistent patterns than steel.