The Naval Surface Warfare Center just released a video showcasing their fully operational railgun system.
BAE's Electromagnetic Railgun can send a canister of hate towards a target at a blistering 4,600 MPH. If said target is another ship... Let's just say that living things in pressurized compartments don't react well to instant decompression.
The railgun has a long way to go. Here's to eventually seeing all of our Battle-Tech and Macross dreams come true.