That is an interesting idea about the temper of the brass but if that were the case why is everyone in this thread saying that it helped so much after they reamed the chamber? Surely everyone isn't using only ammo that is tempered just so. I do admit though that even the CCI was a little difficult before I worked on the cylinder so obviously it did help somewhat that is why I said I had mixed results. Is everyone seeing these same results, success with some brands of ammo but failure with others?