I just built a Seekins PH3 with 17" barrel (mistake on the gunsmith, was supposed to be 18") in 6mm CM and love it. I have a 6.5PRC barrel for it. For the ability to switch calibers within 5 minutes (yes, it's that' fast and easy) it doesn't lock you into a single caliber choice. Trigger and action is premium, you wouldn't be disappointed.