357 Magnum Winchester Silvertip 1250 fps 145 Grain JHP 20 RoundsProven . 357 Magnum Defensive Loads Winchester Silvertip The Winchester Silvertip . 357 Magnum 145 Grain JHP at 1,250 FPS is a proven personal defense load built for revolvers chambered in . 357 Magnum. The Silvertips thin, alloyed copper jacket and lead core are engineered to initiate rapid, controlled expansion at moderate velocities delivering a large, consistent wound channel and effective stopping power while minimizing over penetration risk. The