I have numerous lower receivers from several manufacturers. The only issues Ive ever encountered was one lower where the grip screw whole wasnt threaded deep enough to accept the grip screw for a magpul grip. A quick trip to Ace hardware solved that problem. Another lower had tight clearance for the pivoting bolt catch. We werent sure whether the bolt catch was to thick or the slot in the lower was to thin. We manually filed and sanded the bolt catch to fit. We polished the surface and re-blued the bolt catch and it has been fine for many years. One of these receivers belonged to my brother in law and the other belonged to my brother.
Many people used to complain about RRA mag wells being minimum spec and mags would not always drop free but I never had that problem.
Unless your running a billet upper or want a matched set Ive had no problem using different brands of uppers and lowers. Sometimes the finish doesnt match perfectly but Ive seen Colts with receivers that didnt match in color.
I think it boils down to personal preference and how your going to use your build.
I have 4 RRA, 3 PSA, 3 Anderson, 1 CMMG, 1 Double Star but I have helped Friends and family assemble several other brands of lowers.
Many people used to complain about RRA mag wells being minimum spec and mags would not always drop free but I never had that problem.
Unless your running a billet upper or want a matched set Ive had no problem using different brands of uppers and lowers. Sometimes the finish doesnt match perfectly but Ive seen Colts with receivers that didnt match in color.
I think it boils down to personal preference and how your going to use your build.
I have 4 RRA, 3 PSA, 3 Anderson, 1 CMMG, 1 Double Star but I have helped Friends and family assemble several other brands of lowers.