Here's the deal. The USA mags/pro-mag are total P.O.S. So when the company saw the ban coming, they produced these mags buy the crapload. (pun intended) And gueass what? after 7 years they still have them in their wharehouse. Armalite, and many other quality manufacturers either made themselves or had a wuality company make their USGI type mags, which promptly sold like free snowcones in a Texas summer day.
So, long story short, any hicap mag thats being sold to you must be a pre-ban(made 7 years ago) mag to be legal.