Long Range Hammer
I have hunted with most of the calbers suggested and have used the 300 RUM, 300 Wby and 340 Wby a LOT. I have made extremely long game shots with all the above and highly recommend any of them depending on what you need to harvest way out there. The 300 RUM is the ultimate 30 cal and will kill anything within reason with a 180-200 gn premium bullet out to 750 mtrs and further. My son shoots one as well, and took his first stone sheep last fall at a "ranged" 612 mtrs 2 hits for 2 shots and a 60" Yukon/Alaska moose at a "ranged" 709 mtrs 1 shot.
I love the 300 Wby and have shot it all over the world and find it lacks nothing for long range killing either. The 340 Wby is a fine long range Hammer but it is a significant step up in recoil. The downrange energy is better but not enough over the big 30's to justify. For the animals I packed my 340 for, I was more interested in mid range killing power on bigger, bitier critters and was loading 250 Parts in it.
The big 30's are plenty for all North American (and 99% of the rest of the world's) big game except POSSIBLY the big bears, where long range shooting is not usually required nor recommended. The big 30's are very hard to beat in the long, down range energy department and exceed the 340 when they really get out beyond 500 mtrs because of the extra velocity combined with the higher B.C of the bullets, they are easier to shoot and nothing in the NORMAL realm of hunting cartridges betters them.
The 338 Lapua and 338-378 Wby with heavy bullets, 408 Chevy Tac, 416 Barrett and (of course) the 50 BMG are the first significant step up in long down range performance, but are not conducive to a normal hunting weight rifle IMHO.
The 338 RUM has a design flaw and does not produce the velocities it should given case capacity to bore dia and is the only one of the RUM family with a different case length and design, and it still don't work right. I played with it long ago in a full length 404 case as a wildcat and gave up as it would not exceed the 340 Wby and with some bullets would not even match it.
But hey, who says you have to do it all with one rifle, get one of each, I did.
