Was searching around and couldn't find much on this... Can anyone tell me if i can switch out parts between two different ARs and expect them to run just as good as with their original parts? For example, a Colt 6920 is known to be fairly loose while a Sig M400 is known to be pretty tight. Could I swap out parts between them and expect them to run just as well? What about between two 6920s or two M400s?

I suspect my answer is going to be "not as well" but would they run well enough to be considered reliable?