Looks like the law is pretty clear.
(a) No person shall engage in the business of … manufacturing ammunition, until he has filed an application with and received a license to do so from the Attorney General. The application shall be in such form and contain only that information necessary to determine eligibility for licensing as the Attorney General shall by regulation prescribe and shall include a photograph and fingerprints of the applicant. Each applicant shall pay a fee for obtaining such a license, a separate fee being required for each place in which the applicant is to do business, as follows.
(1) If the applicant is a manufacturer—
(C) of ammunition for firearms, other than ammunition for destructive devices or armor piercing ammunition, a fee of $10 per year.
18 U.S.C. § 921 provides us the definition of ‘ammunition’.
(17)
(A) The term “ammunition” means ammunition or cartridge cases, primers,
bullets, or propellent powder designed for use in ANY FIREARM. (emphasis added)