So, I went to the range the other day, and after putting a box through my PPS .40, the heel of my hand is sore as hell. (haven't been to the range in a year, as I just got back from A'stan) I re-noticed that the stock backstraps are really rough. Is there anywhere that sells different backstraps? I Googled it but did not find anything.

Try throwing some bicycle tire inner tube around it and see if it feels any better...or a Hogue Jr.