Why not roller lock you guimoI'm of a different opinion on that, I think colt mags look out of place, at least on the CMMG lower. The q10 colt lower does look better, but I much prefer the Glock lower.
Eventually is like to make a DI Glock mag ar in 9mm or 45. I like 9mm since the 50rd 9mm drums are fairly cheap and reliable.