HEVI-Shot HEVI-Hammer 20 Gauge 1oz 2 3/4in Shotgun Ammo 3 Shot 25 Rounds. The Bismuth layer is the same shot size as the steel. That small but mighty leading edge of bismuth packs nearly 50percent more knockdown power than the steel layer at 40 yards. Specifications for HEVI-Shot HEVI-Hammer 20 Gauge 1oz 2 3/4 in Shotgun Ammunition: Manufacturer: HEVI-Shot Gauge: 20 Number of Rounds: 25 Shell Length: 2 3/4 in Muzzle Velocity: 1325 ft/s Application: Upland Shotgun Shot Weight: 1 oz Shot Material: Bismuth Lead Free: Yes Application: Hunting Package Contents: HEVI-Shot HEVI-Hammer 20 Gauge 1oz 2.75in Shotgun Ammunition What is HEVI-Shot HEVI-Hammer 20 Gauge 1oz 2 3/4 in Shotgun Ammunition good for? The manufacturer suggests that it is best for upland.HEVI-Shot HS29203: HEVI-Hammer 20 Gauge 1oz 2.75in Shotgun Ammo 3 Shot 25 Rounds