Enjoy backyard shooting with your friends with the Umarex USA Strikeforce .177 Caliber Auto BB Air Gun. This BB air gun uses .177 caliber BB carbines and has a full-length top Picatinny rail to attach scopes, optics and other accessories. The three-position thumb-operated switch allows for easy flipping between automatic and semiautomatic, and the 10-inch profile barrel creates a sleek and realistic look.