Legal Issues of Ammo Manufacture?

You need a Type 6, 7, or 10 FFL, and to produce ammunition consistent with the restrictions of that type of FFL (e.g. DD, AP, or normal). Also probably a corporate entity, good lawyer, and liability insurance.

Plus a lot of money for some very expensive hard to find machines and the guys who know how to put them up and run them.
Heck if it were easy don't you thing the big guys who already have most of that would be doing it?
As it is most marginal US ammo, think .38-55 and .458 Win Mag, is going to be a very tight commodity for the near future, with several manufactures going to alternate years of production, due to Govt. contracts.

You would need a good lawyer to draw up a release of liability statement.

No matter how hard you might try, there will be somebody stupid enough to load hot ammo into a gun that can't handle it.

You also wind up paying alot of extra taxes as being a manufacturer...It almost isn't worth the trouble

Is Old Western Scrounger closing or not? That would have a big bearing on how hard it would be to break in.

Other than licencing with ATF and registration with the US. Dept. of State department of defense trade controls there is no legal requirement for insurance, or knowledge of ballistics. You are responsible for the payment of exise tax on the sale of ammunition and reporting same to ATF on a quarterly basis. No need for corporate entity either as the laws regarding the manufacture and sale of ammunition are not concerned with the structure of your particular business operation.