I am willing to design custom weapons (AND NON-WEAPONIZED TECH) for nations or characters. 
That means you give me a general idea of what you want it to do, and I make it work with science!

For example: The Cartridge Laser Emission Automatic Rifle (CLEAR). Photon crystals (yes, it's a thing, thank Princeton) are stored in isolation chambers (rounds). 
Each round can be discharged entirely, or more slowly, depending on rifle settings. 
Full discharge is a nearly instantaneous release, too many full discharge shots cause the rifle to overheat (lets say 12 per minute, because they're about equivalent to a JAVELIN RPG in energy release). Rifle cooling systems can theoretically handle 20% of a round per second continuously.

How it acts in use: Full discharge shots cause a streak of plasma to form in the air (if present), which collapses with a loud thunderclap. power drop off is dramatic with normal high release rounds, limiting effective range to just under 100 meters.

-This is just a sample, just msg me or reply if you are interested.