Guys helping someone solve a problem they are having with the coated bullets is spot on and a good use of this thread.
I went back and did some checking on some notes I had made while getting ready to use the coating. The wheel weight (clip on weights only) with 2% tin alloy I have been using tested 13.4 BHN average with the Lee tester. I heat treated some (heated in oven 450 degrees then into tap water) and got 26.8 BHN average. When I coated them they lost most of the heat treating hardness. Dropped to 14.5. I decided that the 1 BHN wasn't worth the trouble of heat treating so I just started dropping them in water after the last coating of Hi-Tek. Those are running an average of 15 BHN. Like I said before, I have shot these with 1 1/2" groups 100 yards and no leading out of the .308 at near max load 43 grains of H4895 160 grain bullet gas checked three coats of Hi-Tek.
The wheel weight bullets with no tin that I shot out of the 308 were 117 grains gas checked 43-46 grains of H4895 best group I got out of those was 3" at 100 yards with the 45 grains. With no lead in barrel. The straight wheel weigh bullets have not had the hardness tested. They like the others were dropped in water after the 3rd coat.
One of the guys on this thread, memory gone, uses lino metal in 223. I'm going to test some 223s, if I can get all of my other projects done, that are 49% lino 49% wheel weights and 2% tin. BHN on them is 24.8 after three coats and water dropping after last coat. I'm with Kryogen, I don't like expensive alloys and would rather shoot the most thrifty (my wife says I'm cheap) alloy I can possibly shoot and it work.
I think I'll start dropping in water after they come out of the mold to see if I can gain BHN. That doesn't add a step before I load them like heat treating.
Note: the above listed BHNs and the above listed loads which came out of a loading manual and your results may differ.