Originally Posted by Quentin
Beautiful receivers, Jag!
I've used parts from companies like Spikes Tactical, Daniel Defense, DPMS, Yankee Hill and Magpul and never had any issues with getting 3 AR builds (two in 5.56 and one in 7.62) together. I think if you make sure you use respected brands you won't have any issues building one. Mil-Spec should be Mil-Spec regardless and if they don't go together, there's a problem with the parts.