257 Roberts Hornady Superformance +P 117gr SST 3030 fps 20rdsHornady Superformance +P . 257 Roberts 117gr SST at 3,030 FPS 100200 fps faster than standard . 257 Roberts loads. The SST polymer tipped bullet delivers rapid controlled expansion, deep penetration, and reliable mushrooming with high weight retention. Safe in modern rifles rated for +P pressures. Reloadable brass, non corrosive. 20 rounds per box. Caliber: . 257 Roberts +P Bullet: 117gr SST Velocity: 3,030 FPS 20 rounds Polymer tip, InterLock ring,