Actually, we now have more weapon manufacturers, especially of Stoner-patterned guns like this IAR, than we have ever had before. Raising demand in the face of import restrictions (try getting one of those dirt cheap Norinco AR15s) has created an environment in which every other machine shop is churning out their own receiver sets and bolt carriers groups. Anyone with even the most basic milling machine can purchase forged receiver blanks from suppliers like DSArms and produce serialized firearms faster than a custom wheel shop can turn out tire rims. Our domestic small arms industry is booming.
The production of AR-type rifles is booming. But not of new designs, and not on government contract(s).
Cranking out an existing design like the AR isn’t difficult, and it gets even easier if you have a wire EDM machine for a couple of the operations (eg, the mag well).