Do you hand load, does heavy recoil bother you, how much do you plan to shoot. All these questions make a difference. If you don't reload then the price and availability of ammo becomes a factor. The 300 Ultra mag has more recoil than the 300 WSM. If ammo is a concern and recoil isn't then I would consider the 300 Win mag, it has cheaper and more available ammo. If recoil is a factor then you need to go with one of the standerd cartridges. If ammo and recoil are not a problem than I would pick the 300 WSM because of recoil. I have a 300 RUM but it is a 9 pound rifle and the recoil is not that bad. I don't know how it would be in a lighter weapon and the 300 WSM should have recoil close to a 300 WM which I shoot all the time and I belive is very manageable.