Would these uppers work with standard CMMG/Black Dog/Chiappa mags or do they have some super-duper extra-special Canadaian-made mags and won't run anything else? The reason I'm asking is because I gotta run a match on the 10th and a buddy will loan me his NEA upper but only has 1 mag, while I should get like 5 Black Dog mags next week. I can't run the match with just a single mag, but I can run it if my Black Dog mags will run in that upper.


















































