A bit of digging brought out the 338-416Rigby improved. This case is equal or bigger then the Wby without a belt, excellent brass, and accurate. An instant success. With a 36" barrels, reaching 3300fps is not out of the question. That is serious horsepower. Just drop those numbers into a ballistic program then look at impact velocity and energy at 1500yds on out.
I was surprised to find out that this case was tested by the US Army in the 80's as a LR sniper/material destruction rd. Pity they didn't adopt it. Could you imagine the surplus brass
i read about it, its because it was a belted case.
the 338 lapua is very similar but unbleted.