I just don't see any need to go outside the 300 WM unless you want to build a 1000k monster. You might want to check in with the Long Range Hunting Forum if you are going that route.

Well, I expect from your name that you are sturdy and can shoot! So a stiff barrel is not going to put a dent into you, especially if you are already used to humping 100 pounds of gear. In my USMC days, snipers used Remington 700's, stiff barrel and a 3x9 Redfield scope. (I would go to a different scope brand now.) No reason that won't kill Bambi.

3rd Bn, 9th Marines.... back then.