Back for some more advice! I settled on a Seekins Havak PH2, and mounted a Leupold VX5 3-15 and an APA Little Bastard brake on it. Haven't shot it yet, but loaded up a batch to zero it and a ladder that hopefully gives me promising results.
I stuck with the 168 TTSX's and Lapua brass, and acquired Fed GM215M's, but I have a dilemma with powder weights:
I'm running Ramshot Magnum starting at 78.0 (load data shows max charge of 86.6). I usually load in .5 increments with a ladder, but that'd be 18 different groups I'd have to test. My plan was to increase by 1 grain increments and chase a velocity goal of about 3,200 FPS, then fine tune when I got in the ballpark of my desired velocity.
I realize there's risk of pressure issues with going up by 1 grain, but I'm starting at the minimum and also limited my max charge to 86.0, and with a longer barrel than used in the load data I think I'll find my desired velocity before I hit any pressure. What are your guy's thoughts?