JMO anything in NA which to me includes the big bears a 300 is marginal. Now if your like most meaning upto and including moose then your 280 is more then capable. So i say instead of buying a mag ported 300wsm that may or may not be too much for your tolerance to recoil...unfortunately you'll only know this by shooting the firearm in question with approriated hunting loads! The suggestion is use the money you would have spent on the boss rifle and get into reloading. This will allow you to tailor your 280 rem for whatever you may hunt today and in the future. I reload for 2-280's which have seen varmits to canadian moose fall. Perfect excuse to become a reloader to enjoy the heck out of the sport and this great cartridge.
addition of a better recoil pad is an option.
Just food for thought.
PS I can't help but wonder if your eye relief on your scope isn't short either by afforded or setup proper? I've seen this happen a lot! Can also be tightening up and not flowing with the shot...on the range, seated, expecting the shot, etc Weight or size has less to do with it, then technique.