Frequently the full auto "firearms" you see shooting blanks are actually not firearms in the lagal sense of the word. Designed to fire only blank ammo, cannot chamber of fire ball ammo.
Armed Forces Day in Honolulu- all of the reenactors were carrying replica firearms due to Hawai'ian law. Had folks from pre-settlement native Hawai'ian forces up thru Vietnam. Really like the bagpipers- only in Hawai'i do you have a piper in full kilts and regalia whose name is Nakamura!