Just found this old mold the other day and am quite confused what it could be for. When cast from ww/Pb, 50/50, it has a driving band of .430-.431", but a base of .417". These weigh in at 257 grains and are very round (better than some of my modern molds). Overall length is 0.842". I bought this thinking I might be able to use it in a 44 Mag, but I would not think that the small base would do very well at all. Any ideas what this is for?