If I want to push that much powder, I think a larger bore is more efficient, and def will get better bbl life. That's from a 6.5 lover.
Maybe some Mag folks will like it, Weatherby fans have been hollering and waiting, well some have, about a 264 Wby....concept good, but I just think a 7mm or 30 makes better sense w/that much powder, and I am not a 30 fan, rather a 338 or 9.3 if I NEEDED more than a 270/280 class round, and at that I just shoot the short non-mag rounds......
It will be interesting but recoil should not be light given charge, so that will be found out in short order. No doubt the stats sizzle....
I would likely run a 270/7mm WSM in a short if I wanted something w/LR in a short action, and a simple 7 RM in a long. With good bullets the plain jane RM is highly capable, much brass/ammo and rifles abound.
