I got my BreaKO mercury recoil reduction system from a local gun shop. I got the 9/16" diameter one because that's the one they had and I wasn't aware that there was a better size available until I checked out this Web site, http://www.graco-corp.com/graco/mercury ... ystem.html
In hindsight, I could have ordered one cheaper online and got a better fit.
Here's a link to Limb Saver. http://www.limbsaver.com/ if they don't have your gun stock listed, don't panic, give them a call. More than likely they have one that will fit and get you going in the right direction.
One thing to keep in mind is a gun that fits you is the 1st step in recoil reduction. If your stock is too long for you, you want to have the stock cut to fit before adding a mercury reducer or recoil pad. Cutting the stock will change the recoil pad size and may make it more difficult to find the right size. They'll then ask for simple measurements and send you patterns that you can print and match right to your gun stock. Once you've got the right shape and size, the worst that can happen is the screw holes line up wrong and too close together. My application I had to plug 1 screw hole so I could re drill in the exact correct place. With out plugging the old hole, the drill bit and screw wanted to slide over into the old hole, it was that close. I simple got a small dowel, drilled the old hole out to fit the dowel tight, and glued the dowel in. Let dry, cut and sand the dowel flush, mark and drill new hole for new pad. This is only a problem on very few applications. If they have your gun stock listed, the holes should line up perfectly. Mine was a brand new Mossberg 835 dual comb stock never offered before. Now it's been around a couple years, they probably make a pad that fits now. Of course I'm talking about wood and wood laminate stocks. Filling old, stripped or wrong holes in a synthetic stock is beyond my experience. Probably fill with epoxy, sand flush and re drill?
Shouldn't be a problem, pretty simple stuff.