Yes.... This definitely has potential to work.
I took an extra standard M factory mag today, took the follower out, then hit it with the torch (not directly) while holding it with some channel locks on each side of the feed lips to hold them slightly closer together. After some gentle heating, I let it cool while holding the channel locks tight.
Voila, it works! It also feeds well in the action with 223 rounds... Most of the time. The only problem is that they want to nose dive sometimes when coming out of the mag and get jammed in the receiver against the bottom of the barrel breech. This happens with 2.26 col rounds. Maybe it would work better with longer rounds. I think that is very likely due to the follower not having upward pressure on the front half of the cartridge. So maybe repositioning the spring would do it. I'll have to play with it a little more.