I'm trying to get a handle on the best way to build a corrosion resistant bolt rifle, since I live and hunt in rainy, salt water territory (Washington and Alaska.) I've learned a lot from this forum, and am grateful for the many quality posters here, but I've still got some questions that I hope some of you can answer.

I understand that stainless steel has substantial anti-corrosion benefits, but that it is not immune to corrosion and has some negative characteristics with regard to use in an action. I believe that there are several plating or coating options available that can improve on SS's anti-corrosion properties, but I am interested in seeing opinions on which are the best options -- bearing in mind that I prefer a matte or flat black finish.

Are there other significant drawbacks to SS use in actions besides galling?

Would plated or coated CM be just as corrosion resistant as plated/coated SS? I rather suspect that it would have the same problem as steel hulled boats: susceptible to rust starting from the least little chip or crack in the protective coating.

Can some of the advanced plating or coating products be used to address both the corrosion and galling problems? I know that hard chrome is difficult to impossible to get evenly deposited inside the bore of a barrel, but are there products that can be applied to the inside working of actions given the concerns for tight tolerances? It seems to me that some very thin depositions could conceivably be used throughout the action, and some of the Bear Coat literature seems to indicate that they coat even the inside of the action, but I don't know if any of this is true.

What about TiAlN? It looks very impressive as a tool coating, but I've been able to find out very little about its use on firearms (other than its being mentioned as an option by a couple of custom builders.)

That'll do for now. Thanks for any and all responses.

I know that Dave at Virgin Valley had a barrel black TIN coated. He said that you could drag the barrel across the floor of the shop and it wouldn't even have a scratch on it. He posts here as V.V. Dave. He would have some useful info I'm sure.

As a chemist I'll give you my two cents on corrosion/oxidation prevention in steel alloys.. The best thing I've ever found is to coat a SS barrel with Tetra( a teflon based coating material which bonds to alloy steels). Available at most gun stores. For example, if you coat a 4140 CM barrel with Tetra you can't Blue the steel in hot caustic blueing salts( sodium hydroxide and sodium Nitrate). SS is even more corrosion resistant than CM although salt water is a problem. No gun I've ever coated with Tetra and kept up the treatment ever rusted even under incredibly harsh conditions, try it. you will like it!.-Rob

Some of the old Guides I did work for in Alaska used to coat their rifles and shotguns with a Poly Glycote automotive finish. They would send the guns down every other year for service and the weapons while beat to hell, were in fair shape as far as rust went. Of course, these guy's were from the old school, they would actually clean their guns while in the field and wipe them down when they got wet...


Malm

I've had good luck with Robar's NP-3 coating.

[ 01-22-2003, 11:50: Message edited by: DB Bill ]

Just get an all SS gun. What could be easier than that? Stainless steel has been used on boats for decades. I have many SS things on the boat which is kept on salt water. Some bleed a tiny bit of color that is easily wiped off. Others never show anything.

Nobody would spec. painted carbon steel for a marine application unless it were a throw away item. If SS is properly passivated it will not rust.

As far as the finish goes on SS the bead blasted looks really good and they have no glare. In fact blued steel has a lot more glare.

We are lucky SS guns are available. As of now I have only two but I want more.

Thanks for the responses so far. I'm still confused, though, as to whether any of these metal finishes are applied to the inside of the action, or whether they strictly protect the outside of the gun.

What you normally see in marine and medical applications in stainless is 300 series stainless, which has a high degree of nickel. This allows it to be extremely corrosion resistant, but at the same time, it's a bitch to machine, hence the fact that gun manufacturers use 416 stainless. 416 is much easier to machine, but it's tendency to rust is much higher. If the stainless is passivated, it will eat off most of the free iron that is on the surface of the stainless, but even that won't guarantee that your gun won't rust. In fact, over the thousands of parts that I've manufactured in stainless, and put through the passivation process, I've not been impressed with it's increased corrosion resistance. The only thing that I ever found that really worked on stainless, aside from some of the coatings that have been mentioned above, was to passivate the stainless, then hot caustic blue them in normal steel salts. After the passivation process, the majority of the free iron has been eaten off the part, what's left then gets blued. It's without a doubt, the best finish I've ever used for stainless. The finish that is obtained is a dull grey, not quite silver finish, but still pleasing to the eye. There isn't a hunting enviorment on this planet that it won't hold up to.

The reason gun manufacturers use 916 and 416 stainless is because they contain carbon. Carbon is needed for the heat treatment of firearms. The presence of carbon helps makes the stainless easier to machine, it is responsible for rust, and the presence of carbon makes the stainless used in guns magnetic as well. The 300 series stainless is non magnetic and as Matt stated, is used more in the medical field and for building precision measuring instruments where magnetic influence and corrosion would be a problem...

Malm

InfoSponge,
I came to this forum today to ask the same question as you. When I came to Prince William Sound, Alaska, I found that my blued rifle wasn't meant for here. I've been taking very good care of it over the years, but it's a losing battle.

Go to: http://www.robarguns.com I see that DB Bill likes the NP3 finish he got from them. Here's some of the finishes they offer. I think I'm going to go with them myself.

Roguard- "provides the lubrication and corrosion protection necessary to meet U.S. Military Machine Gun Dry Firing Requirements after 60 days sea water immersion or 1000 hours salt spray MIL-STD-TEST."

NP3- Very accurate and even coatings on all activated surfaces.
No lubrication is needed on opposing surfaces.
Cleaning is minimal, usually requiring only a soft cloth.
Firing for longer periods of time between cleaning, as dirt has no wet or oily surface to cling to.
NP3 has a micro hardness of 48-51 Rockwell as plated (nickel matrix).
NP3 is very corrosion resistant, a 1 mil (.001) coating exceeding 240 hour salt spray test.
NP3 has a high lubricity and low friction co-efficient; therefore, the life expectancy of a firearm will be greatly increased due to the less friction wear.
The coating is strippable with no effect on the base metal, allowing other coatings to be applied or a new coating of NP3 to be applied if necessary.
NP3 plated onto stainless steel guns will stop galling, a problem common the stainless steel guns.
NP3 is a satin grey, non-reflective color ideal for all firearms.
NP3 can be plated to all internal parts giving a smoothness to the action not found with any other coating.
In cases where the NP3 has been perforated, the corrosion shows no tendency to spread or migrate under the coating.

For $290 their site shows that you can get a Roguard finish with NP3 internals. If my wife gets me the birthday present I'm hoping for, I'll be getting this.

Thanks, Whelen. That was very helpful. Robar looks like an impressive operation. Does anyone have anything negative to say about Robar, Roguard, NP3, or electroless nickle?

InfoSponge....just let me add something. John Lazzeroni prides himself in using the best components available for his rifles...and they all get the Robar treatment with NP-3. You will never regret the decision to have your firearm protected by NP-3.

FYI...he also used McMillan MCRT actions, Schneider SS barrels, Jewell triggers, Vais muzzle brakes, McMillan stocks, Sunny Hill bottom metal, and Pachmayr Decelerator recoil pads.