RE: the most exotic cartridge ever
Not sure if anyone is making rifles for 338-06 now, but I believe A-Square was, and is still making ammo for it. Might have been Weatherby made some rifles for it.
It would make a nice chambering, but not sure as how much edge you would have over
a 35Whelen.
Heck, I'd like to see a 338-08 (.338 bullets with 308Win. case), but then we had/have the
358Win., and it didn't take off too well as a factory offering either. Seems like anything over 30calibur doesn't do too well without a magnum moniker, and a belted case.
A shame.