Sen. Dianne Feinstein (D-Calif) proposed a federal assault weapons ban that would be more restrictive than the one that expired a decade ago and slammed by gun control advocates as being full of loopholes, NBC News reported. The proposed ban would prohibit 157 specific guns, including the AR-15 style of semi-automatic rifle, and would require just one "military-style" feature to be prohibited. The last ban, which was implemented in 1994, prohibited 19 varieties of semiautomatic firearms by name, as well as certain kinds of shotguns. It also instituted a test that determined which guns were banned based on whether or not they had two or more “military-style” features, such as a pistol grip, folding rifle stock, or barrel equipped for a silencer. Critics of the last law argue that companies were able to easily bypass the two-feature test by simply removing one of the features, and continue producing what was effectively the same semi-automatic rifle. Sen. Feinstein, who also proposed banning magazines that hold more than ten rounds of ammunition, anticipates an "uphill" battle with Congress as well as the National Rifle Association.