It's a Gauss rifle, Magnetic accellerator cannon, rail gun, whatever you want to call it. I fires a metal slug propelled by magnetic charges through copper rails. _______________________________ =______________________________ Imagine the lines are electro magnetically charged rails, the = is the slug. There should be another line under the = but I couldn't draw one. Now the = is released and the magnetic charge draws it along the barrel (not shown) and it reaches super high speeds, and the charge stops at the end of the rails but momentum keeps the slug moving and so it hits the target. The super high velocities mean that the slug punctures the target armor, then shatters causing even more damage, which is what makes rail guns so powerful.