super177Gamo Swarm Viper 10X GEN3i .177 Cal. 10 Pellet Multi-Shot Inertia Fed Pellet Air Rifle. Hh Power Air Rifle. 1300 fps.Pros These pellets brought down and killed a groundhog up in a tree 40' away with one shot from my new Ruger Air Hawk break barrel .177 I am very impressed with the power of the rifle and the penetration and killing power of these pellets.