I am considering an H&M Black Nitride finish on a pickup/coyote gun for corrosion resistance. A mauser action. What is current experience with this process? How effective is it for corrosion resistance? Is there danger of softening the action? How does the appearance compare to rust blue. Thanks for the help.

For a “truck” gun save yourself a lot of trouble and money and just spray paint it, like every police snipers rifle I’ve ever worked on.

I've used them, sent a 1909 Argentine receiver, CM barrel, trigger guard, etc as a test gun project. Am very happy with results, color is a matt black, haven't RC'd the receiver but it was for a 25-06, finish is very durable, I'd use them again unless maybe it was for a big boomer. There have been debates about the process softening a Mauser receiver because of the heat involved and whether barrel life is extended or not, there are very knowledgeable people on this website who know more than I but again I'm happy with the results. It seems like 50/50 for or against, do your homework, continue to ask questions until you are satisfied one way or another.

Id opt for stainless steel for a truck gun, it holds up best of all, but SS will rust under the harshest of challenges...Ive found a true old world rust blue is the best of all finishes, done right it will last forever. most modern finishes of today don't wear well under abuse...Just look at some of the old English rifles at SCI and at the better gun shows, all rust blue..the downside is old world rust blue is damned expensive from $300 to $500..