You could re-barrel the 280 w/ a 24" and dang near get the results you are looking for. BUT, if you are set on buying a new gun go buy a Tikka T3 in 7 rem mag put a limb saver recoil pad on it and wala ....
I should note that in my 300 WSM I shoot 150 grain Silvertips. The recoil is a lot less with this grain bullet than the 180's
Normally, they dont go the whole way through an animal. I have pulled several out of deer shot between 200 and 400 yards. I memory serves me correctly, the bullet I pulled out of a deer and it only retained 75% of its original weight according to the scale.
I was recently in your shoes, sort of... Was looking for a new rifle that had a bit more performance than my .270win. Really struggled between a 7mm and a 300win mag. Ultimately went with the 300 win mag, in a Christensen Ridgeline. With the muzzle brake, it kicks far less than the .270, to the point where it's nearly not noticeable. The gun is legitimately fun to shoot 40+ rounds at the range. the 300 gives me the ability to sling a big heavy bullet a long way.
Your 280 with a 26 inch barrel would get you into 7mag territory, but then if you just want a new rifle, and who doesn't, go with a 7mm Rem Mag. To me it's the best trade off of recoil and ballistics. The perfect deer caliber too.