HSM Game King 338 Lapua Mag 215 Grain Spitzer Boat Tail Rifle Ammo 20 Bx/ 20. Now HSM has developed an entire lineup of fine hunting ammunition featuring the time-honored Sierra GameKing/Pro-Hunter bullets. Each caliber's individual components have been precisely matched to each GameKing/Pro-Hunter bullet to maximize their potential for accuracy and performance. Specifications for HSM Game King 338 Lapua Mag 215 Grain Spitzer Boat Tail Rifle Ammunition: Manufacturer: HSM Ammunition Caliber: .338 Lapua Magnum Number of Rounds: 20 Bullet Type: Spitzer Boat Tail (SBT) Bullet Weight: 215 grain Cartridge Case Material: Brass Muzzle Velocity: 3138 ft/s Application: Hunting Primer Style: Centerfire What is HSM Game King 338 Lapua Mag 215 Grain Spitzer Boat Tail Rifle Ammunition good for? The manufacturer suggests that it is best for hunting.