The True Velocity 5.56x45mm 69 Grain Sierra MatchKing Rifle Ammo is precision-engineered, polymer-cased ammunition to allow for big improvements over brass-cased ammunition. This composite-cased ammo is much lighter and reduces heat transfer to your firearm. True Velocity offers less deviation in velocity, which gives you improved accuracy. More efficient powder burn also decreases your muzzle flash. True Velocity ammo is not designed for reloading in commercial-grade reloading equipment. These True Velocity rounds are loaded with Sierra's famous MatchKing bullets. Sierra MatchKing Bullets Polymer-cased ammo 30% Lighter than loaded brass Increased accuracy Consistency in muzzle velocity Reduced heat transfer Magnetic retrieval