I have a factory AA 11.5" upper, and so far I am pretty dang happy with it, now I don't shoot a lot, just a half a mag here and their in the back yard. One day I was cleaning my 308 with copper solvent ( mil-tec I think is what I was using ) and the barrel in that ar10 is a bhw 3 groove poly barrel, before I started cleaning it I think it had 50 -80 rounds on it. The patch came out clean, no discolor from the copper or any thing, I was kinda up set lol I though for sure the barrel was or had some copper fouling in it. so I grabbed my AA upper and ran a patch with the solvent down it, and the patch came out blue as all hell. I was thinking wow WTF that barrel is all jacked up and dirty. question is this, I have not tested the barrel with high power scope to see what kind of accuracy the barrel gets, I know it shoots and sighted in with aimpoint pro and it works for me, but should I switch to a polly rifled barrel due to less copper fouling, possibly better accuracy ? I know the aa barrel is qpq which makes it pretty much hard as nails, but whats the hive say ?