I've had great success buying complete rifles, swapping parts in and out. Life was great. Then I even won some gold medals at the National level, too.
I've also had further success taking stripped lower recievers and then building them up with quality parts kits and then winning more medals. Both methods were equally satisfying to do. Just like tweaking my M14's for competition, working on the AR was half the fun.
Hey, maybe it's time for another clinic, but AR this time ?
Not this coming season....