As far as magnums go, put me in the camp with those that like the 7mm Rem. Mag.,if you have a need for a magnum. BUT, it's more cartridge than necessary for most hunting in the lower 48, so i don't hunt with one any longer. I did take this sheep with a 7 Rem. mag....
Like James i choose a 280 Rem. over the 7 mag's... The best reason to have a 7 mag. over a 280 is "if" your hunting moose or big bears, ordecide to shoot at bigger game into the next county... The mag case will drive a 175NP faster than a 280 can, and the 175NP out of a 7 mag. is plenty of cartridge/bullet even for the biggest bears.
DM