Arizona legal definition of a firearm...
ARS 13-3101.
4. "Firearm" means any loaded or unloaded handgun, pistol, revolver, rifle, shotgun or other weapon that will expel, is designed to expel or may readily be converted to expel a projectile
by the action of an explosive. Firearm does not include a firearm in permanently inoperable condition.
Hiskool's technically right, and I would go further to say a supervised range is any property/land that is set aside, public or private, where it is permitted by the owner to shoot (given it's in a manner that's safe to the public, and the participating individuals, such as the various indoor shooting ranges within city limits.) but will an LEO care if the general pop complains? Not so much. Also, Tucson has it's own ordinance restricting airsoft use so Striker is right too...
Sec. 11-1. Air guns, slings, bean shooters, etc.
It shall be unlawful for any person to shoot or discharge any bullet, stone, shot or other missile with or from an air gun, or with or from a sling or an elastic spring or bean shooter or any other like appliance within the city.
(1953 Code, ch. 18, § 1)
Win-win! How awesome is that....
El Con could work...
IF the owners agreed (don't hold your breath) and
IF we could get to and from the area of play without causing a disturbance (gun and gear bags anyone?) and the area of play was isolated so as to not cause alarm for the gen pop.
Bottom line though, It's a nice thought, but not one worth arguing about, hypothetically or otherwise.