Buffalo Bore Ammunition Heavy 44 Rem Mag 305 Gr Hard Cast Lead Flat Nose. This round is designed for super deep penetration at revolver speeds but will mushroom and penetrate less deeply at rifle speeds. This equates to a solid 3 feet of penetration in muscle and bone and at rifle speeds roughly two feet of penetration in muscle and bone. Specifications for Buffalo Bore Ammunition 4A/20 Heavy 44 Rem Mag 305 Gr Hard Cast Lead Flat Nose: Manufacturer: Buffalo Bore Ammunition Caliber: .44 Remington Magnum Number of Rounds: 20 Bullet Type: Hard Cast Flat Nose (HCFN) Bullet Weight: 305 grain Cartridge Case Material: Brass Muzzle Velocity: 1325 ft/s Application: Protection Primer Style: Centerfire