I was under this same decision lately, building a light weight Tikka for mountain hunting. I went with a long action donor, a Mesa altitude stock, hells canyon 23" summit carbon barrel. I pondered caliber for a month. Will us this rifle to hunt steep/dense country from a backpack 90% the time. I wanted knockdown power. I was torn between 7 Saum or 300wsm. After much debate I went 300. Build is still in progress, but it'll be throated with 230fb to shoot 215 Bergers and the heavy eldm line. Should manage 2850+ fps with rl26. That's a lot of juice for a handy 6# rifle. It'll kick like hell in sure, but looking forward to getting it on the range.