[Marcello]

I vaguely remembered something about that thus I have not issued grenades to the field guns.Carabines and pistols only.
I have however issued grenades to some Vasilek mortars
(in my fictional army they would be mounted on special carriages fitted with APUs to keep pace with the infantry and used as direct fire infantry guns/light antitank guns/conventional mortars).They had no problem firing smoke in direct fire but admittedly I did not try indirect fire smoke missions in the artillery menu.