Semi-automatic rifles kill twice as many as other guns, study finds
Evolution of Semi-Automatic Weapons
5 Best Semi-Automatic Rifles for Your Home - 19FortyFive
Experimental semi-automatic rifles, 1919-1931- excluding Garand's and Pedersen's rifles - Springfield Armory National Historic Site (U.S. National Park Service)
A device that can turn a semi-automatic weapon into a machine gun in moments is wreaking havoc on American streets | CNN
What's the difference between a semi-automatic weapon and a machine gun? | HowStuffWorks
Best Semi Automatic Rifles | Sportsman's Warehouse