https://www.youtube.com/watch?v=Biwb...2jR2KOgzC3oiVJ
I have an internet/You Tube friend that is testing all the aspects of Powder Coated Cast Pb HP's and using the .38, .357 & .44 Magnum as the platforms.
His work is exemplary and he tests them in gel blocks for penetration and expansion.
Unlike many of us who use scrounged Pb for our blending, he has ordered pure metals and mixing components as in Sn to keep the work as accurate as possible. Too, he uses gel blocks without layers of denim or simulated meat and bones...I would imagine that aspect may come later, for now he is trying to keep all the variables to a minimum for this basic study of the cast HP.
He gives all the details of his work, listing exact components of Pb and powder and I think anyone who is trying to develop HP loads would benefit from his work...his video work is awesome.
give him a look...c h a r l i e