TMK, while ammunition is somewhat regulated already, it’s even easier to manufacture with minimal resources. Hobbyists have been manufacturing ammunition for a very long time. In the short term, those manufacturers would fill in the demand gap left by factory ammo.

It would certainly make ammunition more expensive, and thus potentially curb unnecessary use, but a lot of that unnecessary use is a big predictor WRT safe use, so I’m not entirely sure the net effect would be positive in the long term either.