My experience with the prefits is you better hold your tongue just the right way to find a perfect fit, because it happens rarily. I have seen them out a touch to not even close so I'd suggest you take the rifle and try matching them up before buying. Failing that option slip on or skip the prefits and go right to the grind to fit. I grind them down on my bench belt sander, match up the holes from the stock pad and drill the holeson the press. Its a pretty simple process, fit is better and here the grind to fits are marginally cheaper to boot.