What is the best way to break in the Hi Cap mags??

[skyfish]

I feel your pain gopher, mine feed well. But about half of mine sit the the cartridges too high, so the bolt dents the shoulder. A little tweaking has helped. I have one 17(15 is all I try), it was the worst. If you shoot the whole mag you won't notice this. I also had to polish the ejector just a tad, that helped as well. Mine had that stovepipe problem, and the brass would get hung up by scraping the lower part of the chamber. I only loaded a little for this round, I do plan on going to a bushing die. That will prolong brass life as well.

I have looked at my 5.56 brass, and in general, ARs' don't pamper brass.