Modern Firearms are defined by the ATF as firearms built after 1898.
Compare“CMMG 55A080BCT Dissent BR4 *CA Compliant 223 Rem/5.56 NATO 10+1 14.50" Black Nitride Medium Taper Threaded Barrel, Coyote Tan Cerakote Aluminum Picatinny Rail Receiver, Magpul SGA Black Polymer Stock” has been added to the compare list