A modern-day automatic rifle firing rifle rounds on full autofire. As a consequence, it is heavy, bulky, and runns out of ammo rather quickly - but it still revolutionaized 20th cenury warfare. Rabble armed with such weapons present a credible threat even to professional armies, and a single gunman can do incredible amounts of damage and threaten large groups of people. It comes as no surprise that this is the favourtie weapon of revolutionaries and tin-pot-dictators the world over.