Gorilla Silverback, 9MM 135gr Solid Copper Subsonic Expanding Projectiles The 135gr is engineered and tuned for maximum expansion with 100% weight retention while limiting over penetration. This product is perfectly designed for home defense or conceal carry. These projectiles are precisely CNC Swiss Lathe Turned and feature a unique patent pending design. Our Silverback ammunition line creates devastating temporary and permanent wound cavities which are created by the aforementioned solid copper projectile. The unique design of the projectiles expands quickly and with insane precision. Click here to browse our selection of 9mm Ammo.