Looking at the current options for metal finishing on a Pre64 Mod 70 with a Krieger chrome moly barrel. Barrel and action work done by Mark at Penrod Precision. This is a synthetic stocked rifle that will be used in wet weather .
1)Not a huge fan of Cerakote, it’s okay but find the finish comes off the sharp edges and scratches. Cerakote also has a bit of the painted on finish look.
2)Hot Caustic Blue, looks and works pretty good. Does rust if not attended to on extended hunts in wet weather
3)Rust Blue , probably not for this rifle

The finish I am most interested in are the Plasma finishes.
4)Black Plasma Nitrided, this finish is interesting . I have this finish on a current manufactured Magnum Mauser 98 .416 Rigby. Have not used this rifle. The Black Plasma Nitride looks great, similar to a rust blue and a very even application .
The concern of mine for the Black Plasma Nitrided finishes is the extreme heat that is needed to apply the finish! Not sure if this is a safe process for heating these actions to such a high degree of heat, especially for the older Mausers, Pre64 Model 70’s , 50’s and 60’s actions,and even newly manufactured actions. Is it safe to heat these actions and barrels to such high degrees of heat?

Is the inside of the barrel coated with the Black Plasma Nitride? What does this high heat do to barrels?

I see where Matt Roberts of MNR Customs has a Early L61 Sako that he did for a customer over on 24 Hour Campfire with this high degree Black Nitride process. Maybe Matt can chime in?

H&M seems to be one of the main players in the Black Plasma Nitride finish. Any of you metal experts have any comments or experience with this extremely high heat metal finish application ? Maybe someone from H&M can reply and tell us why their Plasma Nitride type Finish is safe for our firearms.
4WD

What is the temperature needed?????

I don't know what plasma nitriding is, but I talked to a firm doing gas nitriding; here is the conversation from another thread here. It seems that receivers can be done with no problem. On the barrels, yes, it does harden the bore. As stated in m conversation, the hard layer is so thin that it does not contribute either way to structural integrity; it just makes the surface smoother, as in bolt travel.
It is expensive.
From a previous thread this year:
I just personally spoke at length, with an Engineer from Paulo.
BLUF: Gas Nitriding Process is wholly unsuitable for a Mauser, or any other receiver, in which the parent heat treatment is insufficient.
I explained to him the history and current uses of Mauser receivers. We discussed the DWM made, pre WW1 ones which are sometimes lacking in hardness and case depth. He explained that his process is a superficial layer of hard steel, which is for wear reduction and smoothness; not for resisting shock loading. That is what the original heat treatment is for. He was also shocked to learn that the Mausers are made from 1018 or equivalent material, and were case hardened with bone charcoal. And other methods later, but were still reliant on that process to function correctly. He said, his process would proceed a very hard thin layer, but would need to be hardened first.
He also said that most of the steel he processes is modern alloys and they come to him pre hardened.
So. If you send him a soft receiver, it will come back to you with a thin layer of hardness, but will not be suitable for any use other than what it was before you sent it.
We agreed that there would be no point in having his process done on a case hardened part. Only softer, alloy steels which do not rely on case hardening for their usefulness.

quote:

Originally posted by JTEX:
What is the temperature needed?????

Maybe someone with experience will comment. What I am reading is around 1100F.

4WD

I am not at all looking at the Nitride Process to add hardness to the barrel or action. Hardening the metal seems to be a bi-product or one of the main purposes of the nitride process.

I am interested in the properties of the Nitride Process for corrosion resistance and the quality rich deep blue appearance it seemingly provides. I am thinking the blue surface it provides is durable. The negatives is the unknown with the high temperature required to apply the nitride process to both the action and barrel.


The high temperature required to apply the process is possibly a negative.
The current Magnum Mauser 98 that I have has the Black Plasma Nitride finish and it is very attractive. I would think the Germans at the Mauser/Blaser factory would have extensively tested this process. It seems very few in the gun trades here in the USA are familiar or have experience with the Nitride Process.

quote:

Originally posted by 4WD:
I am not at all looking at the Nitride Process to add hardness to the barrel or action. Hardening the metal seems to be a bi-product or one of the main purposes of the nitride process.

I am interested in the properties of the Nitride Process for corrosion resistance and the quality rich deep blue appearance it seemingly provides. I am thinking the blue surface it provides is durable. The negatives is the unknown with the high temperature required to apply the nitride process to both the action and barrel.


The high temperature required to apply the process is possibly a negative.
The current Magnum Mauser 98 that I have has the Black Plasma Nitride finish and it is very attractive. I would think the Germans at the Mauser/Blaser factory would have extensively tested this process. It seems very few in the gun trades here in the USA are familiar or have experience with the Nitride Process.

It is common place in the AR-15 world, and has some traction among target shooters. We use it on small parts and even screws when we want a black finish with excellent rust resistance.

I do believe it should be considered for hi end custom rifles. It can provide a very attractive finish and the hardening and rust resistance would also be a benefit. Trigger guards, sling mounts, buttplates, scope rings, all those small parts that rust likes to attack. Batch price is high, but you can do a lot of parts in one batch. We just had a couple thousand #10 socket head cap screws done for our handguards. Gives rust resistance with better strength than stainless screws.

John

John

Here is some info I found; and a good article. https://www.industrialheating....iding-process-part-1

It appears that gun parts are done with gas nitriding. Probably best to call the vendor, like I did, and talk to an engineer who actually performs the process on firearms. He told me that is is no problem. But if all you want is the color, and not surface hardness, well, that is the point of it.
From the link above:
"In certain alloys, such as the 4100 and 4300 series, hardness of the nitrided case is modified appreciably by core hardness (Fig. 10). Observe that a decrease in core hardness results in a decrease in case hardness. In order to obtain maximum case hardness, these steels are usually provided with maximum core hardness by tempering at the minimum allowable tempering temperature.

All hardenable steels must be hardened and tempered before being nitrided. The minimum tempering temperature is usually at least 50°F higher than the maximum temperature to be used in nitriding. Typical tempers range from 1150-1350°F (620-730°C)."

I've used H&M on a half-dozen or so project and have always been pleased. What I like about nitriding is that, unlike finishes like Cerakote, it doesn't add dimension to parts.

Interesting stuff...kinda makes me a little apprenhisive with these youngsters fooling around with re- re heat treatingm of firearms when they mayhaps never owned one.

Maybe I overthink!

I have had rifles, actions, barrels and numerous parts nitrided by h&m ( my understanding is it’s salt bath nitriding and around 950 degrees f) but either way I have never had an issue. I believe they do this process for some pretty big manufacturers and if you send them something they are uncomfortable with doing they will return it. It’s not really a coating but more of a hardening process that essentially makes the inside and outside impervious to rust. Supposedly adds barrel life as well. Haven’t shot out one of the barrels yet but when I do I’ll let you know.

I have had one rifle completely done in nitride for something like 7 years now and have never oiled it and it has never rusted.
Also left an action screw that was nitrided by
Them in the cup holder of my work truck for over 2 years. I finally needed it for a project. Pulled it out of the cup holder and wiped the sticky grime off and it looks good as new!

Here’s a rifle Matt Roberts did for me. Sako AV in 300 win mag. He re-shaped the stock,Pillar bedded, free floated, made a new cross bolt,refinished and recheckered, and the metal work was sent to HM for nitriding.Told Matt the reason for the nitride process, the only thing on my boat that refuses to rust is my Glock....

Looks really nice, but think I will set back and see how it washes in the long run.. but hey I do that with all the new and ingenious stuff..

Well...I first thought screw in chokes were just a paasing fad..May be the go to blackening finish of the future

Scuse me...gotta get back to my rust bluing

I think there is some confusion here on the terminology. H&M is obviously performing a "Salt bath nitriding" process. This process is often called black nitride and has several trade names such as "QPQ" or "Melonite" Plasma and/or gas nitriding are different processes and have many variations. The salt bath process is very common on firearms and has all the advantages listed above plus increased barrel life. It is recommended to break in a barrel before having it treated since the bore surface will be so hard. Any roughness in the throat will take much longer to smooth out. I agree it should be considered for a fine firearms finish. I had the barrels on my AR nitrided and I show off the capabilities to people in the shop by taking a file and aggressively rubbing it on the barrel. A file absolutely will not scratch or mark the barrel!

What Nick said^^^^^^

4WD,

Are you thinking of physical vapor deposition (PVD) coatings?

quote:

Originally posted by DavidReed:
4WD,

Are you thinking of physical vapor deposition (PVD) coatings?

David Reed,
Nope.
Go to the John Rigby website and look up the Big Game Rifle - Plasma Nitride
Go to the Mauser website and look up Magnum Mauser 98 - Black Plasma Nitride

4WD

quote:

Originally posted by rgrx1276:
Here’s a rifle Matt Roberts did for me. Sako AV in 300 win mag. He re-shaped the stock,Pillar bedded, free floated, made a new cross bolt,refinished and recheckered, and the metal work was sent to HM for nitriding.Told Matt the reason for the nitride process, the only thing on my boat that refuses to rust is my Glock....

RGRX,
Nice stock work on that older Sako AV. I am a fan of those older Sakos.

Curious why Matt Roberts had your Sako barrel and action Black Nitride Coated by HM Metal Processing but HM would not Black Nitride all of the parts because they said small parts like the screws and small springs would BECOME BRITTLE in the HM Black Nitride Process. What metal finish did you use for the springs and screws for corrosion resistance? Maybe your builder Matt Roberts will comment on why the small parts will become brittle in the HM Black Nitride Process. Is it because of extreme heat?

4WD

Matt didn’t tell me parts would become brittle, I mentioned it to him as it was something I read on the web or the company website, forget which…
If parts didn’t get treated, they remain as they were. MR to the best of my knowledge had not used the process in the past and had it done at my request.

quote:

Originally posted by Duane Wiebe (CG&R):
Interesting stuff...kinda makes me a little apprenhisive with these youngsters fooling around with re- re heat treatingm of firearms when they mayhaps never owned one.

Maybe I overthink!

Duane,

I tend to agree with Duane Wiebe and his experience regarding this new to firearms re-heat treating , Plasma Nitride hardening / coloring/corrosion resistance finish. Changing the metal composition by introducing the high heat required of the Plasma Nitride process on 50-100 year old Sako’s, Model 70’s, and Mauser’s just does not seem the wisest thing to do on these older firearms where the steel has already been processed . Reading more about the Black Plasma Nitride Process tells me the process is more for hardening the metal than providing a corrosion resistant finish and attractive look to the metal. I checked with other old school top tier builder’s with the same level and experience as Duane and not one of them endorsed the Nitride Plasma finishes being offered. I think I will let the aerospace engineers who are also metallurgists play with the nitride plasma finishes and not use the process on my 50-100 year old firearms .
4WD

Hey Lee,
Thanks for the post. Look forward to seeing that rifle in a picture with a moose next year!
That's right, small parts like springs ect can't be nitrided or else they'll become too brittle. There was a handful of those I Cerakoted instead of sending for the black nitride. Non-ferrous metals also can't be nitrided.

quote:

Originally posted by rgrx1276:
Matt didn’t tell me parts would become brittle, I mentioned it to him as it was something I read on the web or the company website, forget which…
If parts didn’t get treated, they remain as they were. MR to the best of my knowledge had not used the process in the past and had it done at my request.

quote:

Originally posted by MNR:
Hey Lee,
Thanks for the post. Look forward to seeing that rifle in a picture with a moose next year!
That's right, small parts like springs ect can't be nitrided or else they'll become too brittle. There was a handful of those I Cerakoted instead of sending for the black nitride. Non-ferrous metals also can't be nitrided.

quote:

Originally posted by rgrx1276:
Matt didn’t tell me parts would become brittle, I mentioned it to him as it was something I read on the web or the company website, forget which…
If parts didn’t get treated, they remain as they were. MR to the best of my knowledge had not used the process in the past and had it done at my request.

MNR,
Did you use the Black Nitride process on the old Sako AV barreled action to re-heat treat or harden the action, barrel and parts? It seems from what I have read the main reason to use the high heat Nitride process is to harden the steel? In addition to the maim purpose of reheat treat /hardening of the steel, the process leaves a blue/black finish on the metal with some form of corrosion resistance. Is it known what the black nitride process does to the rifle barrel when the barrel is also reheat treated and hardened further?
4WD

Hey 4WD,
I really can't speak to the process with any kind of authority. This was the first gun I've sent to H&M for nitriding. However rgrx1276 was interested in the corrosion resistance that nitriding provides. I can add that I was very pleased with the results of H&M's work. Time will tell how it holds up, but from what I've read it holds up much better than other finishes out there, even though it's technically not a finish.

As far as the effects on the barrel, I've only heard that it extends barrel life.