Thank you everyone, like I said I'm pretty new to the AR in fact to semi auto rifle except rimfire. Being a reloader I was never much of a fan of the generally oversized chambers that are common in many models. I was also puzzled about everyone's general lack of concern about headspace and will agree that if you shoot factory loads a little too much isn't necessarily prohibitive as case stretch is really mostly a problem in reducing case life for the reloader if they keep bumping the case neck back.
