Underwood Ammo 10mm Auto 220 Grain Coated Hard Cast Nickel Plated Brass Cased Pistol Ammo 20 Rounds. Specifications for Underwood Ammo 10mm Auto 220 Grain Coated Hard Cast Nickel Plated Brass Cased Pistol Ammunition: Manufacturer: Underwood Ammo Caliber: 10mm Auto Number of Rounds: 20 Bullet Type: Flat Nose (FN) Bullet Weight: 220 grain Cartridge Case Material: Nickel Plated Brass Muzzle Velocity: 1200 ft/s Muzzle Energy: 704 ft-lbs Application: Target Package Type: Box Primer Style: Centerfire Sectional Density: 0.2 Lead Free: No Package Contents: Underwood Ammo 10mm Auto 220 Grain Coated Hard Cast Nickel Plated Brass Cased Pistol Ammo Underwood Ammo 242: 10mm Auto 220 Grain Coated Hard Cast Nickel Plated Brass Cased Pistol Ammo 20 Rounds