In addition to trying any of the other suggestions above...you might want to consider looking into a good shooting vest or jacket. Outlets like Gander Mountain or Cabela' s usually have a good selection, (and frequently gun specialty shops will carry them as well). Prices will generally vary from about $50. and up (as high as you' d care to go). These will have a pad placed on the " shooting shoulder" (usually right side-right handed) and will help reduce recoil even further. The jackets/vests are normally used for shotgunning....but work equally as well when range shooting rifles. Just insure the pad is placed properly to work when benching your rifle.

The nice thing about the vest/jackets is that they work in addition to whatever other solution (like recoil pad) you decide to use!

Best of luck!