Thanks guys, I asked him so hopefully I can get a response. DPMS is frustrating, everytime I google DPMS parts, the mag catch and bolt catch are always different in each "DPMS" kit.
I figured DPMS and ar-10b were the same. On the website I got the upper/lower from it says DPMS, but with the attached file I got from armalite it looks like AR-10b.
ZZ - Tech Note 101 AR-10A AR-10B M15 COMPONENTS 120109 Rev 1.doc
I think the mag catch is fairly tight, as far as does it function I'm not sure yet I've just started building it today. From what I read I figured my lower and upper were an AR-10B and got the according mag catch, but I could try the armalite one.
Says DPMS pattern, and it's not 80%. I'm not sure what this means but this is what made me assume it'd accept pmags, "WIRE EDM MAG-WELL PROFILE IN LOWER- ACCEPTS PMAGS"
I'm building a AR-10 out of a CMT lower and upper, and the PMAG 25 LR/SR I have for it fits very loosely and wiggles around. What could be the issue, or is it just how it is?