I have a Mcmillan stock that has aluminum blocks inbeded into it in the forearm and butt. I also have a set of Wichita sling swivels that I sent to Birdsong to have coated with Black-T. After scrutinizing things, I have come to feel that I may not be happy with the portion of the swivel that will extend above the stock. Not being round, It will not "inlet" down into the fiberglass of the stock, or if it does, there will be a semi-lunar gap where round hole meets rectangular block. I would like to see some closeup pics of these mounts on a rifle stock, and get some feedback from those of you who use them. thanks