I built a 340 Wby on a Rem 700 back in the early nineties before all the "long range rage" and didn't build it specifically with that in mind. Just a 26" tube with the overall idea of a portable (8.5 lbs), 500-yard, elk smack-down rifle which it surely was. Ended up shooting 210-gr TSXs at 3150 or so.

I'd look at the 338 RUM cartridge I guess and see if cases are somewhat obtainable and I don't know about that. The Lapua would work of course but so would the old Wby cartridge if given the right platform. And I'm sure you could go all esoteric with any number of wildcats.

Edit: 340 Wby brass is available and though my rifle wasn't "internet accurate" it would do five in a real 1.5" which for the intended game was ok. I would build more carefully and different now if building a thousand hard rifle.

Last edited by George_De_Vries_3rd; 12/22/15.