 However, the term "AR-15" is a Colt registered trademark and Colt only uses the term to refer to its line of semi-automatic rifles.Therefore, other manufacturers began to market their generic AR-15s under separate designations, although these are all frequently referred to as AR-15s, as are some rifles and carbines that are not even based on the AR-15 design.AR-15 style rifles are available in a wide range of configurations and calibers from a large number of manufacturers.