TribReady: You said - "If I was elk hunting, I'd stick with a .303 Enfield, 8mm mauser of any kind, .308 USGI, or .30-06 USGI of any kind, 6.5 Swede. I don't have all of the ballistics, etc for each, but I personally don't put enough trust in the 7.62x54 for elk".
Yet you would go with a 308??? The 7.62x54R is at least halfway in power twixt the 308 and the 06 and is probably a bit heavier than the 303. It is a very effective cartridge and a personal choice over the 308.
I have hunted whitetail and hogs and bear with the 06, 303, 8mm and 6.5 Swede. They all bring home the bacon, or venison. Mikey.