Hornady sets a new standard for hunting ammunition with the Superformance series. Available with either V-MAX, NTX, SST, CX, or InterLock bullets, the Superformance cartridges boost muzzle velocity by 100 fps to 200 fps, without increasing felt recoil or muzzle rise, and are compatible with virtually any firearm. This advancement in terminal performance is made possible thanks to a scientifically derived propellent that’s been optimized for efficiency. The development of the propellent involved temperature tests between -20° and 140° Fahrenheit, which resulted in extremely stable performance regardless of temperature. Other tests involved firing Superformance cartridges out of progressively shorter barrels, proving that the rounds were highly effective is any length of barrel – including short barreled rifles (SBRs). In addition, Superformance ammunition is safely within SAAMI pressure guidelines. Gas operated firearms are also perfectly safe to use with Superformance ammunition. Features of the Superformance Ammunition: Increases muzzle velocity by 100 fps to 200 fps, without increasing felt recoil or muzzle riseCompatible with virtually any type of firearmEffective in all barrel lengths, including short barreled rifles (SBRs)Safely within SAAMI pressure guidelines Hornady Superformance .257 Roberts+P 117gr Ammunition w/SST Bullets (20/Box) 81353