I was just looking at some AR-15's and was thinking that it would be a little boring to just go with the same old 223. Looking at Accuracy Systems Inc, the offer a few conversions. The ones that caught my eye were the 204 Ruger, 6x45 and the 6 PPC(it may have been a BR though). Anyways, what do you guys would be the better 6mm conversion. I know the 6PPC is a great shooter, but how would it cycle through the AR. The 6x45 is golden, all it is is a simple neck up from the 223 case. Anyone have any experience with either two cartridges in an AR platform? Any thoughts are appreciated.