Private Property owners can very well ask anyone to leave at any time for any reason they so choose, however; if the property in question is owned by The City of Birmingham or if the building in question is supported by tax payer dollars, then, Alabama Code 11-45-1.1 would apply vis a vis.
Remember, although some may be inclined to argue otherwise, clearly established Case Law suggests that where 13A-11-52 and 13A-11-73 conflict the provisions of 13A-11-73 govern, it being the complete revision of the subject matter of carrying Handguns in addition to State Handgun Preemption Law 11-45-1.1.
Additionally, please do not forget about State-wide Firearms Preemption in General. The same is codified 11-80-11(a), and it also preempts gun shows as well. Even though 11-80-11(b) would allow Birmingham to outlaw discharge of Firearms, outside of Lawful Self-Defense, such action would not be applicable to Handguns, such being Preempted further under 11-45-1.1 above. This, too, is evidenced under Alabama Attorney General ruling 2005-127, so filied wherefore on May. 10, 2005.
In short, I would be inclined to believe that the open carrying of aLoaded Handgun into a Gun Show thattakes place in a Public Buildingin Birmingham is perfectly Legal underestablished Alabama Code, provided; that if you carry the Handgun concealed on your person or within a Motor Vehicle, then, you would need to first procure a Pistol Permit from Jefferson County.