In the interest of honesty, I am hopelessly old skool. So take it with a grain of salt...preservative coatings, sheep tallow from Dixie Gun Works, Fluid Film at any auto parts, Frog Lube at gun outlets. I like sheep tallow because it has so many other uses..from full on bullet lube, patch lube, wood stock care, leather care...and it's dirt cheap.
OK, hardness testers. If I had Gnoahhh's money, I would buy a good'un. But since I don't have Gnoahhh's money, I get satisfactory results with "Mars Lumograph" 12 pencil set by Staedtler for about 5 or 6 bucks on ebay, free shipping. There are a few pages of detailed "how to" and pencil hardness to Brinnell hardness equivalency charts on cast boolits. I am a man of legendary frugality, so you should bear that in mind when considering my opinions.
