mine went straight on with no problems. i have a paperwork here somewhere for the smith. but basically it was a slot needed cutting in the pad to allow the thing to slide up and down, i had a new butt pad and it had the slot in it already. also you need extra hole in back of stock so when you close the stock down the spring pin has somewhere to go. all very easy to do. just a drill and either a milling machine or even a wood router will do it.
its a good idea but i do have problems with mine, it keeps dropping down a notch at a time per shot so i have to keep adjusting it. not overly a problem as its on a varmint rifle so its single loaded anyway. i will get to fix the issue one day.