Re: AI .223 mags
The AI mags feed my 223ai formed cases smooth as can be in an a1-3 and badger bottom metal. I have never, ever had an issue with AI mags and the 223ai. I ran mine at the shooters bash, and never had a problem with feeding. I wouldn't have another 223ai built without the mag system and AI mags.
My hunting rifle is a 223ai with a bdl style floor plate (Badger m4), and I had to tweak the internal mag box a bit to let the 223ai brass fit better, thus feeding with no issues. All it takes is a couple of hard tugs on the internal box mag, which in turn grants more real estate in the magbox for the brass to fit. Your standard 223 magbox isn't designed for the blown out cases of 223ai.
I also had my gunsmith lengthen the bdl magbox to allow for longer seating of heavies. I love the rifle.