Expansion in ammunition production is not happening much because of the regulations legislated and enforced by the political/regulator class. The AMMO Act would also have the effect of muzzling the contemporary paradigm of campaigns of hysteria and panic unleashed by spoiled hags running useless offices obese with debt/revenues. Besides, there’s no shortage of demand.
I can tell you with absolute industry insider authority that the limiting factor on production is machinery, which is a long lead time investment.