I actually didn't know how to make the ammo with the original mod, because I couldn't read like an adult.  So I made a plugin to make it craftable at the ammo table.

The costs are really steep, but given how powerful the guns are, I think it fits.  Each ammo recipe yields 5, all of them cost at least 1 fusion core, and assorted relevant ammo and components.

All credit goes to the original authors.

Go endorse their mods!  They're well deserved!

Heavy Weaponry v2
Crafting Workbenches