Law Enforcement Training, Community Relations, And Homeland Security Fundamentals Practice Test

Semi-automatic firearms fire one cartridge per trigger pull while automatically cycling to chamber the next round. After each shot, the energy from the fired cartridge ejects the spent casing and feeds a fresh cartridge from the magazine, so the next round is ready to fire without manual reloading. However, you must release the trigger and pull it again to shoot another round—the action is triggered once per shot, not continuous firing with the trigger held down. This is what distinguishes semi-automatic design from fully automatic firearms, which keep firing as long as the trigger is pressed, and from manually operated systems that require the shooter to chamber each new round by hand. The description that matches this behavior—one cartridge fired per trigger pull with automatic chambering of the next round—is the defining idea here.