When I stop someone and they are carrying a weapon illegaly, I don't make much of a fuss about it unless they are drunk, or are a known criminal.
If I don't know the person I will check them NCIC and run the weapons NCIC and depending on how they look, act, and conduct themselves I may let them go, or issue them a citation and confiscate the weapon.
(So far only weapons I have confiscated involved drugs, alcohol, and felons.)
If they are good people with a gun, they will help me on down the road. One way or another.