How hard would that be to implement? I haven't created mods in Fallout before, but got some experience in other titles. Like a recipe would only need some .txt files right?
I haven't messed with the creation kit since Fallout 3 was still new so dunno.
Main thing would be to make it somewhat rare in shops, even more rare in equipment lists, given how it's both so rare and super expensive.
I'd probably make it on par with uniques like medicine stick for price, and make it super rare in the wild, with only a few places guaranteed to carry one.
Silver Rush, BOS armory merchant, maybe one in Arcades Enclave bunker, with the gun runners having the highest chance of non guaranteed merchants to have one in inventory, or maybe they only get the pistol and ammo.
As for the ammo, I'd have it with a few different requirements, to update the recipient from above:
1 scrap metal produces 20 projectiles.
1 capacitor 1 scrap metal and 1 scrap electronics produce 1 magazine.
Then you combine the two and apply energy ammo to charge it, producing one usable 20rd magazine.
The only downside is figuring out how to make it drop empty mags every 20 rounds, and ideally how to handle partial mags.
If it were in 4 I'd just treat it like a fusion core and make each one have a separate charge.
Edit:
Maybe have an inventory item that opens a dialogue tree of options, such as recharging/reloading spent mags.
Would need to get into the scripting and dick around to see what could be made to work, even if it's as tedious as having separate items for mags with 0-20 rounds to drop, assuming some amazing autist has t already made a partial mags mod to use here.
Of course then there's ammo types, for the projectile with the usual HP/AP mechanichics.
And weapon mods.....
Full auto, allows full auto at a few different rates (faster rates increase weapon degredation).
Iron sights/scoped. Add a few optic options, from 1X red dots to magnified optics.
Furniture: swap the wooden furniture for other textures, some may decrease weight slightly.
Paint: texture swaps for the non furniture parts.
Sling/strap, affects holster animation (if doable)