Underwood Ammo .50 Action Express 300 Grain Jacketed Hollow Point Nickel Plated Brass Cased Pistol Ammo 20 Rounds. Specifications for Underwood Ammo .50 Action Express 300 Grain Jacketed Hollow Point Nickel Plated Brass Cased Pistol Ammunition: Manufacturer: Underwood Ammo Caliber: .50 Action Express Number of Rounds: 20 Bullet Type: Jacketed Hollow Point (JHP) Bullet Weight: 300 grain Cartridge Case Material: Nickel Plated Brass Muzzle Velocity: 1580 ft/s Muzzle Energy: 1663 ft-lbs Application: Hunting Package Type: Box Primer Style: Centerfire Lead Free: No Package Contents: Underwood Ammo .50 Action Express 300 Grain Jacketed Hollow Point Nickel Plated Brass Cased Pistol Ammo Underwood Ammo 510: .50 Action Express 300 Grain Jacketed Hollow Point Nickel Plated Brass Cased Pistol Ammo 20 Rounds