Does it matter if the bore is plugged during a standard "hot blue"? Will the blueing chemicals damage the barrel's rifling if the bore is not plugged? I've heard different opinions on this. If you are a professional refinisher that does not plug the bore, please explain why the blueing salts will not harm the bore during the blueing process.
Bore plugging is done with cold blue processes commonly referred to as rust bluing. There is no purpose served by plugging the bore when hot bluing as this causes virtually zero dimensional change in the metal. Any typical materials that could be used for plugs will not stand up to the heat of the process and will contaminate the bluing salts.
This does no "harm" to the bore because the process in the interior is exactly the same as what is happening on the outside. It doesn't "harm" the exterior does it? As a matter of fact, since the iron oxide formed in the bluing process is harder than the base metal it may actually be marginally beneficial.
you plug the bore if you are going to "parkerize" (Zinc or manganese phosphate) not for hot bluing, do not know of anyone who ever did in all the years we've been refinishing, as well as at some of the factories we spent time at or the shops we worked for................
Hybrid Mode
