Sierra Bullets BlitzKing Rifle Bullets 6mm Flat Base FB 55 grain 500 Bullets/Box. The nose tips of these bullets are made of a proprietary acetyl resin compound and the sharp tips improve the ballistic coefficient over the traditional flatbase spitzer bullet design. The 55 grain #1502 has a flatbase. The jackets are thin for enhanced accuracy and explosive expansion but are capable of withstanding high velocities. These bullets are designed to be fired at muzzle velocities up to 4000 fps. For handguns chambered in 6mm TCU 6mm PPC 6mm Benchrest Remington these BlitzKing bullets are superbly accurate and have devastating expansion on varmints and small game at velocities achievable in these handgun cartridges in single-shot pistols. Specifications for Sierra Bullets BlitzKing 55 gr. 6mm FB Rifle Bullets: Manufacturer: Sierra Bullets Gun Type: Rifle Bullet Type: Flat Base (FB) Bullet Weight: 55 grain Projectile Caliber: .243 Caliber Diameter: 0.243 in Sectional Density: 0.133 Country of Origin: USA Package Contents: Sierra Bullets BlitzKing 55 gr. 6mm FB Rifle Bullets Sierra Bullets 1502C: BlitzKing Rifle Bullets 6mm Flat Base FB 55 grain 500 Bullets/Box