I was referring to rifleman's quote that even clip on's aren't always pure lead. I think he meant stick ons. Just a typo I suspect
As to water drop, it makes quite a difference if there is antimony *and* trace arsenic as clip weights have. A small amount of tin is needed to keep the antimony in solution if I understand right, and this configuration pretty much defines clip weights. LA silhouette club is awesome for info.
Water drop makes a HUGE difference though. I highly recommend the process if you want to stretch out WW alloy. It's a bit seat of the pants for drop temp, but when the mold gets hot enough, you can sort of establish a set temp based on the sprue hardening time.
I do wish I had some tin for my mix though. I suspect my plumbing lead has little or none and WW's don't have much.
As to using this mix for 9mm, I load 9mm, .40, and .357 sig and would not use this mix for them. These are all higher pressure (30,000-40,000 psi). Much higher than .45 acp that I am loading with this mix. I was thinking that I can't really get away with mixing the plumbing lead in for fear of dropping the hardness too much. In short, I highly doubt it would be adequate hardness. .45 acp for context is more like 20,000 psi on the upper end. When I worked up my .45 load, the hottest ones leaded the barrel, so it's *just* hard enough. But I am using power pistol for this load though and PP is somewhat finicky with cast boolits.
My wheel weight only mix (with just a little bit of stick-on lead) water dropped to 26, but I have to pay for WW's. That would barely be hard enough to survive 9mm. You can heat treat to around 30 bhn with just clip weights, but it requires a bit of science and a toaster oven
Conventional wisdom currently holds that powdercoating still requires the same hardness, but I suspect it may be wrong. Soft bullets lead up the barrel when the charge pressure overcomes the tensile strength of the boolit and gas cuts. Since PC boolits are well protected from gas cutting, in theory the hardness is of little concern. Similar to plated bullets and for the same reasons. I intend to give it a try with .357 sig as the test, but need to get a new mold for it since the long ogive of my rn mold in .356" is too long to get the OAL right for .357 sig.
Oh, one last note: My numbers may seem exaggerated due to how I took them: I got 9.5 after the boolit was cool to the touch after air cooling. They would have hardened up more by 24 hours- or even an hour. I don't know how much but I realized right away that it would not be enough, so I didn't wait, but dumped them back in the pot to start water dropping. So it's likely that the difference between air cooling with my mix is more like 11 or 12 bhn for air cooled and 18-20 for water drop. At six hours I was worried when I was testing in the range of 15 bhn but it continued to climb.
