I am preparing to start casting 45 70 405gr HBFN bullets w/diameter of .460 and will start with the 3031 I have on hand. I have just acquired plenty of lead from an old x-ray door and considering a lead/tin alloy. I have seen various posts on different boards with conflicting information and I am looking for advice from individuals experienced with this issue. I have seen posts with alloy of 1to20 tin/lead up to 1,300fps and 1to10 tin/lead up to 1600fps. Any information is appreciated.