I over annealed some basic Bell cases (well over 2 bucks apiece) forming some obscure BP cartridge cases for a project. Brass will work harden, don't know if that is the right term, but anyway I put them through a 2 week cycle freezer to 140 deg tap water and they slowly hardened back up to 75 to 85 Brinnel Hardness. Estimated with home shop Mickey Mouse tester.

Well this is a fine pickle we're in, should'a listened to Joe McCarthy and George Orwell I guess.