I don't think loaded ammunition is classified as an explosive at least at the federal level and I am fairly sure Arizona doesn't classify it as an explosive , if it was there are strict federal and state storage laws and it wouldn't be sitting on the shelf at Wal-Mart.
As far as I can find the law is silent on the concealment of magazines.
Remember this is Arizona not California.
§ 173.50 Class 1—Definitions.
(a) Explosive. For the purpose of this
subchapter, an explosive means any substance
or article, including a device,
which is designed to function by explosion
(i.e., an extremely rapid release of
gas and heat) or which, by chemical reaction
within itself, is able to function
in a similar manner even if not designed
to function by explosion, unless
the substance or article is otherwise
classed under the provision of this subchapter.
"Small Arms Ammunition. Ammunition is classified as a Division 1.1, 1.2, 1.3, or 1.4 explosive, depending on the degree of hazard. Ammunition that is regulated as a Class 1 explosive and designed to be fired from a pistol, revolver, rifle, or shotgun, as well as associated primers and blank cartridges (including those designed for tools)"
Is this not right? I got this info a while back from another forum, Please correct me if i'm wrong.