Marijuana and guns? ATF says "No!" The Bureau of Alcohol, Tobacco, Firearms, and Explosives, or ATF, has issued an important notice about changes to Form 4473, the Firearms Transaction Record. Form 4473 is the federally mandated form that must be filled out by any person who acquires a firearm from a federally licensed dealer. The notice of changes is extremely important for FFL's, customers, and gun owners generally. It is particularly important for persons trying to strike a balance between gun rights and medical care - expecially when it comes to the use of marijuana as medicine.