Here in Arizona, it is legal to carry an AR-15, AKM, etc. (pre- or postban) IN A NON-THREATENING MANNER. Although, I've not seen one EVER as an open carry weapon, it sure would turn some heads.
What would the mode of carry be? Slung in some manner? Australian carry? Giles tactical sling? The fact that I'm asking in a well armed open carry State, puts the lie to the Brady Bunch's mad ravings.
Florida is not an open carry state, but there are unusual exceptions. After Hurricane Andrew, I saw many folks armed with both AR's and AK's patrolling neighborhoods to keep out the looter elements. Cops would stop to chat with these individuals and not even blink at the slung weapon. Most were slung African style (muzzle down) or with a Giles rig. I find African style on my weak side an extremely fast movement to the ready position.