Weatherby Select Plus Rifle Ammo 338-378 Wby Mag 262 gr Hammer Custom 3500 fps 20/ct 3D73ECA9 W. Another Weatherby wildcat first introduced in the 1960s. Specifications for Weatherby Select Plus Rifle Ammunition 338-378 Wby Mag 262 gr Hammer Custom 3500 fps 20/ct 3D73ECA9: Manufacturer: Weatherby Caliber: .338-378 Weatherby Magnum Number of Rounds: 20 Bullet Weight: 262 grain Muzzle Velocity: 3500 ft/s Features of Weatherby Select Plus Rifle Ammunition 338-378 Wby Mag 262 gr Hammer Custom 3500 fps 20/ct: Ultimate cartridge for long-range big game hunting Introduced in the 1960s Package Contents: Weatherby Select Plus Rifle Ammunition 338-378 Wby Mag 262 gr Hammer Custom 3500 fps 20/ct This is the ultimate cartridge for long-range big game hunting. Another Weatherby wildcat first introduced in the 1960s. WMM333262HCB