I needed one for my Brocock. I got a bipod sling mount from PA. Next, I used some 2 part epoxy putty. I put some Glad Wrap on the stock where the mount would be, put the putty on the adaptor placed over the plastic wrap, then mounted the bipod/picatinny adaptor. When it was tight the epoxy putty squeezed out to fill the adaptor and made a perfect countour. Once it is hard remove the adaptor and take off the plastic wrap. I also placed a piece of leather between the adaptor and the stock (no marks on the stock). It fit perfectly.