I don't know a whole lot about your rifle, but I do have a quick fix to your woes. Once you're sure you're sighted in- get off the bench. I don't know why, but nothing hurts as bad as bench shooting. Learn good practical positions such as sitting, prone, and standing.
When you're sitting at a bench, your bones line up differently and don't offer as much 'give' to absorb the recoil. Instead of your upper body acting like a shock absorber, it's a wall. Rather than allowing your rifle to 'push' your shoulder back (like when standing), it hits
a shoulder offering considerably more resistance, due to the way your upper body is positioned.
That is one of the biggest reasons I've been trying to figure out how to build a light weight, portable, standing
rest for heavy load development. Right now, I'm leaning toward something adjustable, that will slide in the receiver hitch of my truck. Even if that isn't the most stable
choice, it seems to be a good compromise for size, weight, and utility.
GunXpatriot, don't spend your money on a Pachmayr Decelerator recoil pad. The XL7's pad is as good, or better. You'll just end up making a 1-for-1 swap for a different brand name, with no real benefit.
I think the biggest reason for the number of recommendations, is that the members are unfamiliar with the stock pad on the X7s.