browningautorifleicon - originally I was going to find a screw of the right head and length of known threading and pick up a tap & die set to match. Now I've actually found an original screw so, as you said, anyone know the threading spec on these? I'm still going to need to get a tap & dies set to tap the bipod head (I'm building the unofficial Northern Ireland conversion to go with my AN/PVS-2 & IIWS topcover).