I had a Rem 700 in 300 WinMag, and finally, after 10yrs, decided that the abuse at the bench just wasn't worth the marginal gains in performance over many standard calibers. If I were in your shoes, I'd look seriously at the 280 Rem or 280 AI. The 280 AI is right on the heels of the 7RemMag with less recoil and noise. Out past 300yds, it's all the gun you'll need. I actually went slightly smaller and got a 7mm-08 in a lightweight short action bolt gun. This is still a viable 300yd deer gun with less recoil than any of the others mentioned here.
As has been mentioned, the 25-06, 270 and 30-06 will all work, also. The 25-06 won't carry as much energy as far as the other long action rounds will due to the lighter weight bullets. Will the deer notice?? Probably wouldn't be able to tell the difference between anything from the 7mm-08 up to the 300WinMag at anything less than 300yds.
Good luck ... Crayfish