Flux Compression Generators

Sometimes called "bottled lightning", FCGs use high powered explosives to compress an electric current into an extremely short but extremely sharp power spike. The resulting pulse is powerful enough to generate a significant EMP, and indeed these devices first saw primary use as non-nuclear EMP generating devices.

The device is similar to a bullet in that it destroys itself after being fired, and indeed with sufficient miniaturization the technology has been made compact enough to slide into some firearm magazines. These take advantage of the explosive release of gas generated to propel a slug, while simultaneously using the burst of electrical power to feed a set of magnetic rails or coils. The result is a hybrid gas/electromagnetic weapon.

These weapons do require a significant level of electrical and mechanical engineering and overall sophistication though, because the EMP must successfully be muffled (or redirected) each time the weapon is fired.