I used to read gun magazines - would buy one while traveling or when bored. I hate to say this, but I have to agree with others here - most are nothing more than promotional tools for the manufactures of guns, ammo and accessories. Since about 1996, around the time that the internet became the beginning of what it is today, I haven't found the need to read any gun magazines.
The biggest problem with gun magazines is that none will do a truly critical review of any gun. No torture tests, no "this gun can't hit the side of a barn".... or "this gun has been reported to have slides crack...." - you get it. Just pretty pictures, and not even of the gun's guts, which is what I'm most interested in.
If someone really wants to come up with a new idea for a gun magazine, they would include in each issue at least one gun completely stripped down to it's tiniest components with high-res detailed photos of each (significant) part. And, include a technical analysis of the manufacturing process and quality of all of the parts of that particular gun. Now, there's a gun magazine I'd pay some of my hard earned money for.