41 C.F.R. § 102-40.75 – Firearms.

(a) You must submit reports and transfer documents on excess firearms to GSA. GSA will approve transfers of firearms only to those Federal agencies authorized to acquire firearms for official use, and may require additional written justification from the requesting agency. GSA will not transfer or donate surplus firearms to non-Federal recipients.
(b) You must not abandon firearms. You must destroy unneeded firearms by crushing, cutting, breaking, or deforming each firearm in a manner to ensure that each firearm is rendered completely inoperable and incapable of being made operable for any purpose except the recovery of basic material content. Destruction of firearms must be performed by an entity authorized by your agency head or designee. The destruction must be witnessed by two additional agency employees authorized by the agency head or designee.
(c) Surplus firearms may be sold only for scrap after total destruction as described in paragraph (b) of this section to ensure that the firearms are rendered completely inoperative and to preclude their being made operative.
1. (1) Except as provided in paragraph (c)(2) of this section, firearms received as foreign gifts may be offered for transfer to Federal agencies or sold to the gift recipient. If sold to the gift recipient, a certification signed by the gift recipient certifying compliance with all Federal, State, and local laws regarding purchase and possession of firearms must be received by the gift recipient's agency and the agency conducting the sale prior to the sale and release of such firearm to the gift recipient.
2. (2) Firearms subject to the NFA that are received as foreign gifts cannot be lawfully transferred to an individual gift recipient. These firearms must remain the property of the United States. All firearms must also be transferred, shipped, received, and possessed in accordance with the Gun Control Act of 1968.
(d) You may exchange or sell non-excess, non-surplus firearms in FSC Class 1005 only with the original equipment manufacturer consistent with part 102-39 of this subchapter.
(e) Firearms that are forfeited, voluntarily abandoned, or unclaimed as described in 40 U.S.C. 1306 and 40 U.S.C. 552, must be reported to GSA for disposal.