Shiven, regularly I shoot my .308 with a McMillan HTG stock but also shoot an AR, Cetme, Mosin Nagants and a 45-70 Sharps. The recoil from the Nagants is worse than the 300WM 700P because they only have a steel butt pad. Actually I felt the recoil from my friend's 700P in .308 was worse than my 300WM because of the thin butt pad. You really shouldn't have much trouble with recoil and that rifle. I load up 220 HPBT loads that are traveling about 2700fps and it's not bad at all. Yes you can feel it but it won't make you cry
Omaha, the Wetherby round will be a bit heavier recoiling and will feel even worse from a light rifle. Your eye relief should be about the same whether you are benched or shooting in the field so if you don't think it's enough you should get a different scope. But if you don't want to, just hold the rifle snug in your shoulder and get a recoil pad if you need one. Whenever I see someone who takes one in the eye it's because they are holding the rifle light and anticipateing recoil. Give it a good snug hold in your shoulder, know that you're going to feel the recoil so don't be suprised by it when it comes and squeeze the trigger. Don't pull it too hard into your shoulder because you'll get too much muscle tension and start to shake but firmly will work. Good luck.
By the way what do you mean by "sand bags on the shoulder "? On the back of the shoulder to hold you down? Or between the rifle and your shoulder? And it's always a good idea to use eye protection when shooting.