I just checked and with Ammo Factory + Super Duper, 1 Stable Flux + 1 Ultracite scrap turns into 120 rounds of .45 ammo
I have about 500 stable flux and 2000 ultracite scrap in my junk box and I have literally never sought them out, it just accumulated from raids and boss events

So I'm in trouble after I craft... 60,000 rounds. Oof.

Even then I currently feel a bizarre urge to throw together a Prime Fixer and just do expeditions until I've banked a quarter million to go with my quarter million Ultracite Plasma Cartridges

THE FOMO'S GOT ME