Lloyd - interesting findings you have there. Buncha years ago when I was working up my homebrewed 40 caliber I found that dropping slugs from a RCBS 40170 mold (170 gn 40 caliber swc) that with straight wheelweights the slugs dropped at 185 and over 4.3 of WW231 were the most accurate load/slug I have ever shot from a Gold Cup - even more accurate than the 45. When I mixed a 'proper' #2 alloy they would drop at 180 gns, but when I sweetened the mixture with 10% Linotype they dropped at 170 gns exactly - and they were extremely accurate over the heaviest charges I could shoot through the piece - used them for both silhouette and hunting and they would easily take the ram at 200 yds and shoot through a whitetail at about 75 yds. Mikey.