To the extent permitted by federal law and by the terms of any contract between the Virginia National Guard and a privately owned facility, any member of the Virginia National Guard who possesses a valid concealed handgun permit issued pursuant to Article 6.1 (§ 18.2-307.1 et seq.) of Chapter 7 of Title 18.2 shall be permitted to possess a concealed handgun owned by such member at all facilities of the Virginia National Guard and at all privately owned facilities under contract with the Virginia National Guard. Nothing herein precludes the commanding officer of any member from prohibiting such member from possessing a concealed handgun while such member is participating in any training or other exercises where the commanding officer determines that (i) such possession would interfere with the conduct of such training or other exercises, (ii) such possession may result in mission impairment, or (iii) the member is unfit to carry a handgun.