Modern Firearms are defined by the ATF as firearms built after 1898.
Compare“Vktr Industries V31100916617 VK-1 5.56mm 30+1 10.50" Black Steel Threaded Barrel, Black Armor Cerakote 9.85" VK-1 Handguard, Black Synthetic SB Tactical SBA3 Brace, Black Magpul K2 Grip, Ambidextrous” has been added to the compare list