So how does CO Amendment 64 affect one's answer to question 11e on BATFE's form 4473 ?

"Are you an unlawful user of, or addicted to, marijuana or any depressant..."

Fed law USC 18.922(d)(3) :
"(d) It shall be unlawful for any person to sell or otherwise dispose of any firearm or ammunition to any person knowing or having reasonable cause to believe that such person - (3) is an unlawful user of or addicted to any controlled substance (as defined in section 102 of the Controlled Substances Act (21 U.S.C. 802));"
Note: Form 4473 says "user", in the present tense...as in currently using. It does not say "has used", "used", "will use.

Note: USC 18 922(d)(3) applies to FFLs (and ammo sellers, like Walmart) and says they cannot transfer a gun or sell ammo to MJ "users".

What responsibility do FFLs and ammo sellers have to ensure they are not selling/transferring to a MJ user, from a Federal perspective? ?