The process is like as described above, like a case hardening. Unless H&M is different I always leave mine in a tub of water. The QPQ salt needs to be removed. I posted in the passed an email from an Army armor and his vast experience with it. He did a lot of testing in a machine rest. His opinion was no increase in velocity, no loss in accuracy, but a greatly increased barrel life and a lot better corrosion resistance.
I have a very nice custom woodstocked 40x rimfire with a SS barrel. I like the rust blued look, so I high polished the barrel and did the Melonite QPQ and it looks like a nice rust blued barrel. .
