Licensed gun dealers already can't sell guns to buyers who answer "yes" when a required form asks them if they are "an unlawful user of, or addicted to," marijuana or other controlled substances.
A Sept. 21 letter from the Bureau of Alcohol, Tobacco, Firearms and Explosives also says dealers can't sell a gun or ammunition if they have "reasonable cause to believe" the buyer is using controlled substances, even if the state allows it.
U.S. attorney's spokeswoman Jessica Fehr says the memo reiterates existing policy.
Gary Marbut of the Montana Shooting Sports Association says the policy denies constitutionally protected gun rights to individuals who are following state law.
