If they are indeed using the method described by Mr. Pittelko above which he says he actually witnessed, then that is a form of rust bluing, but it's not what most would call the "traditional" method of rust bluing. It's an "express" method, which saves quite a lot of time. There is a difference in the finish that can be obtained with the two methods. While the Express or Belgian blue methods can and do give some very nice finishes, they are not generally considered equal to the finish that a truly skilled craftsman can achieve using the old very slow "traditional" method which requires MUCH more time. Their web site description may be taking a few liberties with words, not at all unusual in advertising nowadays. I don't mean to knock the express method, but it's not as good generally as a well done "traditional" slow rust blue method. I have done both, the express is much easier and quicker, just not as good for a real custom shotgun or rifle project.
