Crosman R1 4.5mm (BB) .177 Caliber Full Auto Air Rifle - Black - The Crosman Full Auto R1 BB air rifle maximizes backyard fun! Fueled by two 12-gram CO2 cartridges and a 25 round drop-out magazine, you will have target cans flying in no time. The rifle features a genuine feel, familiar controls, and an intense 1400 round per minute rate of fire, all at a jaw-dropping rate of up to 430 fps. Even better, the rifle is fully customizable with a 6 position adjustable stock, AR-compatible buttstock/pistol grip, and a Picatinny rail that provides endless accessory mounting opportunities.