Get the .300 Wby, don't look back. Greatest .300 out there. Stuff it full of 7828, magnum primer, and 180 grain Nosler Partition and you're set.
The WSMs are an oxymoron - if you want magnum performance, get a real one. If you need a light rifle - get a standard cartridge with a light 22" barrel.
I find an 8 3/4# .300 Wby a great hunting rifle. A 180 grain .308 bullet at 3200 fps is among the flattest tragectories out there.
