Winchester Super-X Super Speed Rimfire Ammo shoots a copper-plated lead bullet at slightly higher velocities than standard “High Velocity” .22 ammunition to flatten trajectory, hit harder, and enhance reliable function in some semi-auto firearms. Winchester Super-X rimfire ammunition is manufactured to exceedingly high standards with reliable priming, and uniform powder charges and bullet dimensions to yield consistent accuracy from one box to the next. Copper-plated bullets, clean-burning powder, and priming contribute to maintaining clean firearm actions for reliable function. Super-X Super Speed Rimfire Ammo is an excellent choice for plinking, target practice, varmint and small game hunting. Enhanced super speed velocity Manufactured to exceedingly high standards Maximum accuracy and reliability Copper-plated lead bullet Clean-burning powder Reliable priming