
reddit user zebralemur has made the world’s most powerful civilian made electro-magnetic railgun. A railgun for those who don’t know is a type of weapon that uses alternating electric currents to accelerate a slug to super speeds. No explosion necessary. It’s usually very powerful and very dangerous. But also very difficult, and very dangerous to make. 
It took them over 2 years to acquire all of the capacitors necessary for this project, and he somehow managed to get them for an average cost of $46 each, when they go new for over $800 apparently. So that’s a score. The rest of the cost of the build he doesn’t go into too much. But I imagine it’s probably north of $10,000 total. And it doesn’t look like it’s any more powerful then a standard 12 gauge shotgun, but it’s way cooler, that’s for sure.
It is a first version, so I’m sure it suffers from the cost overruns, and R&D that version 1 of everything does, so I think if they put their mind to it, they could get the total price down quite a bit. Especially once they get the economies of scale involved. And, since it’s not any more dangerous then a regular rifle, or any more accurate, I don’t think they’d have trouble with the ATF, but they probably would.

I like the “bullets” or slugs really, they remind me of teeth, aluminum teeth that are traveling at a few hundred miles per hour, and will probably travel straight through me if given the chance.
Take a look at his Imgur album to see a very detailed process of how it looks and works, and just how awesome it really is. And before that, here’s one more gif of the crazy:
