Sierra BlitzKing Bullets BlitzKing bullets are designed for explosive expansion in varmints and small game with accuracy characteristics similar to the MatchKing target bullets. BlitzKing bullet tips are made of a proprietary acetyl resin compound, and the copper jackets are thin for enhanced accuracy and explosive expansion. Lighter 22 caliber BlitzKings can be fired at muzzle velocities of up to 4400 fps. The lightest 6mm BlitzKing bullets can be fired at velocities of up to 4000 fps. Mfg: Sierra Bullets, Inc.