Hornady BLACK .223 Rem 75 Grain Centerfire Rifle Ammo is optimized for excellent performance in modern sporting rifle-type semi-auto rifles. Hornady BLACK ammunition feeds and functions in a variety of platforms, including direct impingement, gas piston, suppressed, unsuppressed, inertia, bolt, pump, supersonic, subsonic, rifle, carbine, or pistol. Superefficient propellants, designed for use in short barrels, result in a 15% to 20% temperature reduction, delivering a progressive burn rate that burns clean with minimal flash. Hornady BLACK Rifle Ammo is offered in a variety of bullet options to match your rifling twist, and your intended target. Loaded with Hornady brass casings. Optimized for modern sporting rifle-style semi-auto rifles Functions with a variety of platforms Superefficient propellants Burns clean with minimal flash Offered in a variety of bullet options Hornady brass casings