Hold your horses there fellas! I had the same issue with my Remington 700 S/S in 300 RUM. Ripped that tupperware stock off it and got a HS Precision stock on it with a longer LOP and went to a Leupold VXIII from a Bushnell 3200 for the eye relief and now its no problem to shoot. Do yourself a favour and look at getting a custom stock for it before altering the barrel....could be the right ticket for you too!
While a properly fitted stock such as the H-S and more importantly an upgraded recoil pad will make some difference, it will not begin to compare to the recoil reduction of a quality muzzle brake like the Holland QD's I recommend.
I have installed them on alot of RUM rounds and they basically turn the recoil into that of a 270 class rifle with no other changes needed to the rifle.
The installation of a Kick-Eez recoil pad along with the brake will make the big 300 feel like a 25-06.
I do agree that a brake shoudl be fitted only as a last resort and only if the owner plans on keeping the rifle because once you alter the factory barrel your resale value is gone.
Still with a restocking job to an H-S stock running in the $300 level and the brake installation running $165, you get more for your buck with the brake installation in my opinion.
Just do not plan to get full price if you try to sale the rifle on the used market. Just the nature of the beast!
Allen Precision Shooting
Home of the Allen Magnum, Allen Xpress and Allen Tactical Wildcats and the Painkiller Muzzle brakes.