HPBT Rifle Rounds Features This 338 Lapua ammo from the Hunting Shack uses a Hollow Point Boat Tail bullet with a grain weight of 250. HPBT Rifle Rounds Specifications Brand: HSM Category: Centerfire Rifle Rounds Caliber: 338 Lapua Magnum Model: 338 Lapua Series: HPBT Bullet Weight: 250 GR Rounds Per Box: 20 Casing Material: Brass Application: Performance / Protection Boxes Per Case: 10 Bullet Type: Hollow Point Boat Tail Muzzle Energy: 4705 ft lbs Muzzle Velocity: 2911 fps