Is there anyone who has any input on an issue I am having cold bluing? I have a Remington 760 bdl I am trying to cold blue, I am having good results with everything except the reciever. I realize cold bluing isn't necessarily the best option for redoing an entire gun but I am on a budget. I am using Birchwood Casey perma blue and the action tube/barrel seems to be taking it fine but when I try putting the bluing on the reciever it takes in some places but mostly just rolls off. Is it possible the reciever is a different metal that won't work with this? Any info would help.