Huh?? No actually it's not. I would think it would be awkard (Open carry or not) to walk around walmat,the mall or mcdonalds with a M4 ot Ak strapped across your body. And as a Police Officer responding to a person carrying this type weapon (open carry or Not) I would probably challenge him/her until I can identify their status.
Additionally I would imagine that having the strapped M4 or AK would make it some what cumbersome going into bathrooms etc etc (securing the weapon) SO please lets be realistic here Generally when people (IN the know) speak about magazine capacity generally they are talking about Hi cap PISTOL Magazines (12 to 15 rounds).
Usually its the Mall comandos that wanna carry M4 AK type weapons in public