Hot bluing A400 barrels

[Reloader89]

just checking with some guys on here that hot blue, i have 2 a400 barrels that a fella wants blued, is there gonna be any issue with the liner thats on the inside of the barrel where it goes into action its def a different type of metal, not expecting it to take bluing but dont want it to disappear either, i believe i did one of these years ago and had no issue but just wanted to check! thanks all!!

 

[Reloader89]

any hot bluers have some input?

 

[guntech]

I would not hot blue two different metals as described... hot bluing is a very caustic solution at close to 300 degree for possibly 20 or 30 minutes... and it gets in every where and is hard to 'kill' the caustic action.

Or possibly contact Beretta for a much more qualified answer...