This is the simple part, but I guess I should have made it a little more clear. Lay the weight on the cavity on a mold half, then mark where the lube grooves are touching with a sharpy marker. Then just put it back on the bolt, chuck it into your press, and cut the corresponding grooves into it so it will sit in the mold cavity and allow the mold to close. It doesn't have to be a perfect match to the actual boolit grooves, just so the mold will close tight and there is no wobble inside the cavity by the weight (Preferably no spinning either--best if it's a tight fit).