The stock Remington pad isn't all that bad. More effective pads would include the Kick Eze pad, the various Pachmyers, especially the Decelerator, and the Gooey pads the folks over on trapshooters.com are talking about.
Also, if you mount a new pad and don't mind it looking a little odd, don't trim that pad down to fit the wood. Larger area means less pressure at any point.
The important thing is to get the stock fitting you. Lots of old threads on this.