Eviscerator...
The local gun shows here usually have plenty of limbsavers at a table or two. Where are you, exactly? Also, you can order them from
http://www.cabelas.com/ and the like, on-line (cheaper than paying for parking and entry to the gun shows, even with shipping!).
Recommendation: go to Limbsaver site and get the measurements you want, unless you just want a slip-on. Know before you go.
Anyway, as far as shouldering the gun, if you're "shouldering" it at all, you will probably hurt, either from the bruise, or from the force of recoil stretching your shoulder. It should really be called "chesting" the gun. I finally learned that from shotgunning. Put the gun on the meat of your upper pec, rather than out on your anterior delt. Just watch for your clavicle! Try that.
Also, the harder you hold the gun against you, the less space it has to accelerate and slam you. A common technique is to use your trigger hand to push the butt as hard as you can against your upper chest, and use your forward hand to push AWAY somewhat. You seat the gun with your trigger hand, to avoid slamming it against you when it recoils, but you use the forward hand to help fight against the recoil. Sounds wierd, but it's worth trying. Or try the other way around. See which way gives you the best accuracy and recoil absorption.
The worst thing to do is let the gun "free recoil", where it just hammers your body. You have to hold it firmly, and make your body move with the gun as much as possible, if that makes sense.
Here are too many articles about it. Despite Chuck Hawks' ability to get people PO'ed, there's good stuff here. Just use your own judgment; it's not Holy Scripture, or anything, just a collection of nice, short articles.
http://www.chuckhawks.com/index2d.rifles.htm
All of that said, 40 rounds of a big game centerfire round, through a bolt action with no pad, is as much as I'd generally enjoy shooting one way or another, or more. Less if it's a magnum round. A lot less. While the 8x57 is less punishing than a .30-06 or heavier round, it does fall somewhere between 7mm-08 and a .308.
That, along with inherent accuracy and lower cost, is why die-hard paper punchers like the .22 centerfire cartridges.