RIO Ammunition Royal BlueSteel Super Magnum 12 Gauge 3.5 1-3/8 Oz BB. These shells were specifically designed for nontoxic waterfowl hunting applications guaranteed to perform in even the most adverse conditions. If you are looking for a reliable and high-quality game load specifically for waterfowl hunting look no further than the Royal Blue Steel line of game loads from Rio. These loads come in both 12-gauge and 20-gauge sizes capable of delivering impressive muzzle velocities of up to 1550 feet per second. Specifications for RIO Ammunition RBSSM40BB Royal BlueSteel Super Magnum 12 Gauge 3.5" 1-3/8 Oz BB: Manufacturer: RIO Ammunition Gauge: 12 Number of Rounds: 25 Shot Size: BB Shell Length: 3 1/2 in Muzzle Velocity: 1550 ft/s Shotgun Shot Weight: 1 3/8 oz Primer Style: Centerfire Velocity: 1550 fps Package Contents: RIO Ammunition RBSSM40BB Royal BlueSteel Super Magnum 12 Gauge 3.5" 1-3/8 Oz BB RIO Ammunition RBSSM40BB Royal BlueSteel Super Magnum 12 Gauge 3.5 1-3/8 Oz BB