it has took a little while but i may have found the answer. my buddy did no real testing for clean barrel vs dirty barrel. the loads were developed from a mostly copper free barrel and velocity was on the higher side. i chorny'd the load not to long after we first noticed the change and the loads were a little running slow, i assumed it was the powder at the time. all this time i had assumed he was properly cleaning the barrel. finally after having to clean his barrel myself we started seeing the results we had seen initially from the lapua brass. with these things now in mind, i chrony'd 2 batches of hornady brass. some was freshly annealed some was not. the freshly annealed brass was running slower then the brass with about 10 sizings. im concluding that our loads are on the tail end of a optimal harmonic node/apex and dropping velocity off more then 25 fps will hinder accuracy in my friends rifle. the downside is that we are pretty much running as hot as any .308 should ever be run and cannot reach a little deeper into the harmonic node. 45 grains of rl 15 is not rated by all sources to be safe for a 178/180 grain bullet (we are going off alliant data).