I have heard a lot about nitride coatings and their very high level of protection against corrosion.

I own Blaser 93 rifles with multiple barrels. I understand that these are nitride coated. I can attest that they are scratch and rust proof.

I would like to build a non-Blaser all-weather rifle and am thinking that nitride coating may be the best way to go.

The rifle will be a .300 RUM and would also benefit, or so I'm told, from a nitrided bore.

Now, having said all of the above, I must also say that I don't have a clue as to whether this is a good or a bad idea, or even do-able, especially as regards coating the bore.

I would be grateful for any information, suggestions or advice on this subject.

Thanks.

I was first introduced to nitriding (Melonite/Black Nitride) by a bench rest shooter that I do some work for. I have since had many barrels treated. It is a bath, so both inside and out are treated. The goal of the bench rest guys and myself, is to extend barrel life on those high intensity chamberings that are described as "barrel burners", as the process increases surface hardness besides the other properties you mentioned. The process can be used on both stainless steel and CM. Both treaters that I am familiar with (H&M and MMI Tru-Tech) now only do small batches at a "batch" price. They'll do one barrel for the "batch" price, but it is quit high for one barrel. Best to send several to defer the costs. And, it's worth mentioning, only 'new' barrels are prefered for treatment as those with any heat wear (fire cracking) do no respond well.

silvers, Joel Kendrick has an agent for MMI-Tru-Tec that will take 1 barrel at a time. I'm sure it would be $100 or less. The US Military is doing a boat load of them.

I talked to Joel not long ago (within the past 6 months) and he told me that "Rodney" was no longer doing that. The corporation had determined that it was "a conflict of interest". Now, maybe he has someone else. He directed me to a couple of different companies (I've got 'um wrote down, somewhere) and I checked with them. At the price they quoted me for one barrel I decided I'd just make 'batch orders' myself as I have requests from my customers, and do enough barrel work, to do so thru my shop. H&M had a better 'batch' price and good turn around times (2-3 weeks, usually) where as, when I used "Rodney", sometimes I waited for 6-8+ weeks for return of my barrels. Add another 3-5 weeks to gather up 4-6 barrels to ship as a batch and we're talking a considerable amount of time. As you should know, customers these days have no patients.

Joel wanted me to be the go to guy after Rodney quit doing them or left for his own endeavors.I just didn't want to fool with it. His pricing to me was very fair, but I would have the expense and trouble to ship to him, after getting them back I would have to ship them back to the owners. More time and expense. I don't do barrel work for the public any longer.

Michael, to your original question, The 'blued/blackened' finish that's left behind from nitride treatment is tough. Tougher than most other finishes I'm familiar with. As for 'rust resistant', I don't know. I never let the 'rust bugs' get a chance to set in. I get 'um treated for longevity and no other reason. I hear ya', Butch. Taking barrels in and sending them to the treater and getting them back to their owners could be a real pain for low return (everyone wants a "deal"). You could spend all your time on the phone/e-mailing those customers who want to know the day and hour when they will have their barrel back and why it's taking sooo long. I usually only send barrels that I have done the work on, although, I occasionally make exceptions.

Email from a US Army Armour.

Butch

I was the Armorer for the Army Reserve Shooting Team for over a decade so I do have quite a bit of experience with both processes.

As I am sure you know, most G.I. barrels are made from chrome molly steel which is more susceptible to corrosion than stainless steel. Chrome lining is used on G.I. bores both to extend their shooting life and to protect them from corrosion that can be a problem in battlefield conditions where maintenance is sometimes sporadic or insufficient. Chrome lining does a pretty good job of protecting battlefield weapons. One of the objections to chrome lining is that it is thought to decrease accuracy. This seems to be a valid criticism and is backed up by machine rest tests I have conducted of identical barrels (same manufacturer but half chrome lined and half not).

As you are aware most barrel "wear" is in the throat area. So eventually the hot gasses from the burning of the gunpowder will eat thru the chrome lining at the throat. It is rumored that at this point accuracy will plummet but I have not found that to be true. (Or if true, it is overstated or maybe only occurs for that short period when there is both chrome and bare steel in the throat simultaneously - just at the point of initial break thru.) Chrome lined barrels can continue to shoot well for thousands of rounds after the bare barrel steel at the back of the barrel (throat) has been exposed due to erosion of the chrome lining. Another criticism of chrome lining is that it can flake off later in the life of the barrel resulting in poor accuracy. Obviously, this could also cause maintenance problems if the user is depending on the chrome to ward off corrosion and thus is careless in his bore cleaning. If corrosion is allowed to occur pitting will result and that will ruin accuracy for sure.

Barrel pitting was one of the reasons I got involved in Salt Bath Nitriding. I was loosing nearly as many expensive match grade barrels to improper maintenance (causing pitting) as I was to wear out. This was under the relatively benign target shooting conditions. Obviously given the reputation of degraded accuracy, using chrome lining wasn't an option. So for the past couple of years I have been Salt Bath Nitriding all of my match barrels and haven't had a single one exhibit any pitting. During that 2 yr. period shooters have put anywhere from a few hundred rounds to thousands of rounds on said barrels. I don't know how long the coating will persist so at this point I am still evaluating it as a preservative. I don't know what will happen in another year or two when these barrels get more wear on them. Salt Bath Nitriding goes on both inside of the bore and on the outside surface. So, instead of 2 manufacturing steps you have combined them into one. Salt Bath Nitriding doesn't degrade accuracy one iota, unlike chrome lining. This was the first thing that I verified when I began using the process. I broke in a bunch of barrels and then machine rest tested them for group. I recorded and kept the targets, cleaned up the barrels, and sent them to MMi TruTec for the Isonite process. When they came back I reassembled them on the same receivers with the same torque settings, same bolt carrier assemblies, same flash suppressors, etc. Then they were retested with the same ammo lots. NO degradation in accuracy and about a 1% increase in muzzle velocity.

Chrome lined barrels seem to clean up rather easily after a range session. I found the ease of cleaning of Isonite coated barrels to be similar to chrome lined barrels. The Isonite barrels clean up the easiest of any non chrome lined barrels I have ever used. Isonite can be applied to either stainless or chrome molly but the factory needs to know what steel you are sending them because the application process varies a bit. Again, I only have about 2 yr. of cleaning experience with Salt Bath Nitrided barrels. I don't know if the ease of cleaning will continue as the barrels get more rounds on them. Generally speaking, most non coated barrels get harder to clean later in life. Although stainless has a reputation of being corrosion resistant it isn't corrosion proof (I have had plenty of them return pitted) so I coat both my C.M. and my SS barrels. The Isonite on the outside of the stainless barrels cuts reflection down so my shooters like it.

I mentioned flaking of chrome lining inside the bore. Joel Kendrick is my contact at MMi TruTec, the company in Arkansas that does my Salt Bath Nitriding (they call it Isonite). He was mentioning using the Salt Bath Nitriding inside the bore prior to chrome lining it to get a better adhesion. He is currently working with one of the military contractors (maybe F.N., but don't quote me on that) relative to this process. He has given me permission to give out his contact information so I have cc'd him in my reply to you. He can give you the specifics of any testing and evaluation that has been done relative to this process and can give you quotes, etc. should you just be interested in the Isonite by itself as I use it.

One last quick note on chrome lining. Such barrels have the reputation of changing point of impact when heated up. I have found this to be very true. It may be due to the way the different metals (chrome molly and chrome) expand inside the bore. What ever the reason, it does happen and, again, this was verified on a state of the art machine rest. Isonite doesn't exhibit this characteristic.

I am sure you are well aware of some of the things I covered. Lacking specific questions, I just sort of used a shotgun approach which ended up being fairly long. If I left anything unanswered please feel free to get back to me. I have enabled my Spam Blocker to allow your e-mails to come in with out the automated hate responses that Earth Link sends out. I am sure Joel would also be glad to clarify the technical aspects of the Salt Bath Nitriding process. So far I am very pleased with it.

Best of luck!
Carlos

Great information. Seems like a good idea.

Thank you, gentlemen.

Jim,
I will email Joel and get contact info.

Joel's email is joelkndrck@aol.com
Phone number is 704 616 6442

Joel said Rock Creek barrels is the go to place.

I have a 300 Wby on a SAKO L-61R that I melonited some time ago. I don't keep round counts on hunting guns but at least 200 rounds of hot 200 gr loads and I cannot detect any change in the throat with a bore scope. Everthing is nitrided excepth springs, small screws and the scope bases which are rust blued.

As for corrosion, this gun is used in deep South Texas, has been in and out of cases with sweaty hands over and over and gets left in the gun room or trucks pretty much unattended. I don't think I've oiled the outside in 2, maybe three years and there is no sign of wear or other issues:

It's great stuff but not invincible as I found it with a super hot 20ppc on a prairie dog shoot. About 500 rounds in a day and I toasted that barrel.

Adam

I have used and can recommend H&M.

It's great stuff but not invincible as I found it with a super hot 20ppc on a prairie dog shoot. About 500 rounds in a day and I toasted that barrel.

Adam

Adam,
What is your cure for that?

Another barrel, the toasted one was a Rock. It got replaced with a Shilen and sold that rifle with an unchambered barrel. I still have some of my barrels treated but since I can do all of my work now it's actually (to me) a step back price wise. All of my interest had shifted to ultra small cartridges or stupidly large. Not many high intensity chambers left in my house.

Adam

Adam,
I do my own work and can't see how of at least doubling barrel life is a step back.

It's not that doubling the life is the step back. I live in BFE Ohio now and I shoot maybe six rounds per week. So the likelihood I'll wear a barrel out is slim, therefore the process itself is not needed in my case. If I lived in PD country you'd bet everyone of my barrels would be treated.

Adam

Not many who offer this service, it seems. Only Rock Creek or H&M?