HSM 300BLK4N Match 300 Blackout 220 Gr Hollow Point Boat Tail HPBT. The best components time-honored crafting make the difference. Specifications for HSM 300BLK4N Match 300 Blackout 220 Gr Hollow Point Boat Tail (HPBT): Manufacturer: HSM Ammunition Caliber: .300 AAC Blackout Number of Rounds: 20 Bullet Type: Boat Tail Hollow Point (BTHP) Bullet Weight: 220 grain Cartridge Case Material: Brass Muzzle Velocity: 1000 ft/s Application: Target Primer Style: Centerfire What is HSM 300BLK4N Match 300 Blackout 220 Gr Hollow Point Boat Tail (HPBT) good for? The manufacturer suggests that it is good for target.