I feel if anyone/company had gone thru the trouble of developing Nanite based ammo, it would be unintellegent/unprofitable NOT to have a single weapon which fired different projectiles, to use the Nanite ammo. Not only that it would be easier to Create/Make a MultiProjWeapon that it would to have a single ammo sorce from nanites at least at my current understanding of reality
Scorpio Slasher: ... What about you boy, what do hate?
Marcus: ... Bullies. Tiny d*ck egotists who hurt people for no reason, make people lock their doors at night. People who make general existence worse, people like you.