Try soaking the end of the barrel in an inch or so of concentrated Simple Green cleaner in the jugs they sell at the Home Improvement (dont cut it...use it full strength). I once removed the thin chrome from a flash suppressor this way. If it works, you'll have to build a soak tank for the barreled action out of some pvc pipe from Lowes, and invest in a couple of gallons of SG concentrated cleaner. Sometimes real alkaline substances like oven cleaner (or anything with lye in it - use safety gloves and goggles if you do this) can strip thin chrome plateing as well. You wont be able to do much with the receiver though even if you do remove the chrome....krag receivers dont take cold blueing well at all. High nickel content perhaps?