The bismuth high performance non-toxic rounds have 24% greater density than steel and each configuration is loaded to optimal velocities, maximizing ballistic performance.It's softer than steel and higher performance, so it won't harm barrels and is safe in any choke.Gauge: 16 GaugeType: BismuthLength: 2.75"Ounces: 1 ozShot Size: 5Muzzle Velocity: 1300 fpsRounds Per Box: 25Boxes Per Case: 10Shot Type: BuckshotApplication: Upland,WaterfowlHazair: Yes