Subject to the needs of the Army, the Secretary of the Army may sell ammunition for military weapons which are used for avalanche-control purposes to any State (or entity of a State) or to any other non-Federal entity that has been authorized by a State to use those weapons in that State for avalanche-control purposes. Sales of ammunition under this section shall be on a reimbursable basis and shall be subject to the condition that the ammunition be used only for avalanche-control purposes.