I've been looking into getting one of those G36 mags for my XM8 and simply modifying it. So I've been searching around, and apparantly more than one company makes the G36 high cap mags. Are these all identical and simply labelled with different names? Or are there some companies that have lower quality than others? It's my assumption that they're all the same and simply labelled differently, but I'd rather be sure before wasting my money.
It is safer to assume that LPEG mags are not compatable between companies. Since you're planning on moding the mag to fit, you might be better off moding your existing XM8 mag to take the G36 hi-cap internals, if the G36 doesn't fit.