Beretta PX4 Storm .177 Caliber Steel BB Airgun Pistol Single/double action CO2 powered Blow back repeater Magazine holds BBs and pellets 16 shots overall capacity PX4 Storm 16-shot repeater Accessory rail under the barrel Shoots BBs or pellets Weight: 1.6 Caliber: .177 Pellet Kindly refer the user manual attached below for troubleshooting steps and instructions.