With the release of the 6MM ARC, it seems that 6mm AR chambered barrels are about as rare as hens teeth. I built a 6mm AR using an X-caliber barrel a few years ago that performs really well. But like many other barrel makers, they no longer offer 6mm AR as a chamber option. Is there anyone making/chambering a quality 6mm AR barrel? I'd like to build another 6mm AR. Thx!