Modern Firearms are defined by the ATF as firearms built after 1898.
Compare“Gforce Arms GFY1BRNZ GFY-1 USA 12 Gauge Semi-Auto 3" 5+1 18.50" Black Threaded Barrel, Bronze Cerakote Aluminum Receiver w/Picatinny Rail, Bronze Bullpup Polymer Stock, Polymer Grip” has been added to the compare list