You might also consider the 7mm Weatherby. The 7mm STW is a long cartridge, and requires a long action. The Remington 700 would work, the Weatherby Mark V action will to, but others won't, unless modified. The 7mm Weatherby is right on the heals of the STW, but fits a standard action.

well the stw is a fine caliber indeed, but if ur in the mountains why not go with, a 7mm-o8 or the new 7mmWSM? both short action that will work perfect in 24'' barrels and lighter guns, but not too light. The kick from my .270WSM which i also recomend is quite the mule with my light savage rifle. just my opinion

I faced same questions,,, and decided on 280 Ackley...I get great accuracy with Nosler Accubonds and with Nosler Partitions (three shots within an inch or so, usually two touching and a third within a MOA). Chrony readings of 3200 fps at ten feet in front of muzzle. proven killer of Himalayan tahr (mountain goat) at ranges of up to 430 yards (lasered) for me. and all in a standard action and 8 pound rifle (can easily be made from 7 to 9 pounds).

Can shoot commercial 280 ammo when needed. And just different enought to make me wonder why ever try to go with a "magnum" round?

Oh, did I mention fun to shoot.

STW will fit in a M70 with no problem. They chambered it for a while even.
Great round. Overbore by most standards, but if you want heavy-hitting long-range performance, that's where you have to go.