I have found Permatex works best for me. http://www.rimfirecentral.com/forums...d.php?t=645761
I have used it to make support pads for a 20" hammer forged factory, and a Kidd .920. After casting my pads I cut them to a length of 1.5" to 2.5". I have found that pads made to the correct thickness, for just support, without excess pressure work best.
In my case I have found a pad in front of the take down, and, or at the tip to work best. It can be one or the other, or a combination of both.
I have used mine in a OEM laminate Target stock.
Edit. Mine is free floated, so a business card will slide the length of the channel, when the pads are not in.