300 Win mag is a little more then a 7mm rem mag, a little more sharp. The 300 RUM is in a class all its own for recoil. Standing it may be tolerable, but on a bench, it is intense to say the least. Can you put a box thru the 7mm at a sitting, or can you handle 3" 12 ga mag loads? If so then you can likely tolerate the RUM, but I would recommend the limbsaver recoil pad to help.