I took the Remington r3 pad $19 ( cheap) from bass pro and modified it to fit my pistol grip stock on my sp10
The Remington r3 is softer and more easy to damage than a sims , but is softer .....soaks up recoil ....
Take your recoil pad off your sb2 and bring it with you to bass pro and match it up pad to pad - with the ones they have in stock and you might find a close or exact fit , pay attention to the angles and width of the pads