I've had good luck and bad luck with ER Shaw. The bad luck was a long time ago.

I have Shilen and Douglas barrels also. If I were wanting 1/2 MOA I'd probably go with either and get their "premium". If I were building a hunting rifle I'd probably go with ER Shaw especially with the calibers you're talking about.. The last rifle I built was with ER Shaw - a 375 Whelen AI. I only have Iron sights on it, but it's plenty accurate for what I wanted it for. The bore looks excellent. It doesn't foul with copper or lead.

I prefer classic.
Semper Fi
I used to run with the hare. Now I'm envious of the tortoise and I do my own stunts but rarely intentionally