If you use pellets, the manufacturer suggests that you use only wadcutters. CZ P-09 Duty pistol Uses a 12-gram CO2 cartridge 16rd removable pellet and BB magazine (stick mag with 8rd rotary mag on each end and accepts either lead pellets or steel BBs) Blowback Rifled barrel Looks like the firearm Fixed sights (2 whited dots on rear sight, 1 white dot on front sight) Manual safety Weaver accessory rail Threaded muzzle The manufacturer states this gun delivers 492 fps. Our tech department tested it with 5.1-grain pellets and got 412 fps max velocity. Steel BBs delivered a max velocity of 390 fps.