I've always thought that any of those would be cool. throw the 8mm-300RUM in there as well. I think that the main problem with the idea is avalibility of bullets of high b.c.
I would really like to see someone this.
Agreed, the lack of high BC bullets, or a good selection of any type of bullets for that matter, is what killed the 8mm Rem Mags popularity. I have been toying with the idea of a 338-8mm Rem Mag, also know as a 338 Galliard i believe. This and the 250gr 338 berger VLDs once they come out would make an awsome combo, under the 338 Edge in performance, equaly "cheap" to shoot and better barrel life.
I think that is why there arent many high BC 8mm bulets, the 338s are so close, and there arent any non wildcat cartirdges to really use heavy 8mm high BC bullets.
The 8mm-340 Wby does exist...well, sort of. It is called the 8mm Remington Magnum. Unless I am mistaken, case capacities would be nearly identical. That is right as far as no high BC bullets being available for the 8mm. About the best one out there is the 220 gr Sierra Gameking spitzer boat tail. It has a BC of a little over .500. Start it out at 3000 fps and it is still no slouch out to about 600 yards.