This is the most powerful mobile electromagnetic railgun built by a non-government. A railgun is a device that accelerates a conductive projectile using extremely high current and electromagnetism. No explosive powder required. Just batteries. This page shows many of the steps required to make one.
The gun is portable, but the power supply is not. Still, cool project.
(Score: 0) by Anonymous Coward on Saturday November 14 2015, @08:01PM
For an imgur submission, it is quite good.