Most of the coil guns we've seen online have been non-portable, garage build projects. This is the best version of a portable coil gun that we've seen yet. The design is quite impressive, and features a display that shows you the charging level in the capacitors.
It's quite the advanced design – the gun uses a 12V Nickel-metal battery, specially modified to be fast discharging, a controller circuit that limits the amount of voltage sent to the capacitors, and a bolt action loading system. The builder (Jason) has been working on his project for 2+ years, and the end result is amazing. You can view his report here.
[via Hacked Gadgets]