Nitride a barrel?

[65WSM]

I have had fifteen barrels, salt bath nitrided, Some using non toxic salts (Melonited) and arsenic salts, both new barrels and used. I have worn out seven 17 Reminton, 6.5 WSM, 6.5-284 Win .22-250 AI, .204 Ruger, .20 PPC. Since I use HBN coated bullets, I can take advantage of the speed from reduction of the bore drag. Obviously, I am a proponent of the process. I have a .22 BR and .20 PPC barrel I am waiting on processing now.

I have a couple of newer reloading dies that are nitrided. One is a RCBS .204 Ruger "small base" sizer I use for my Shilen AR barrel and the other is a Whidden .20 BR custom. They are amazing. Much smoother to operate.

 

[HRM Johnny]

I just had my first rifle barrel, bolt and action nitride treated. I have less than 30 rounds down the barrel, but it does seem to shoot fast. Reloading manuals show about 150 fps slower than what I am getting. Time will tell how it works out. Look forward to hearing other other people's experiences.

Please keep us updated!

 

[HRM Johnny]

FYI
I found these previous Posts.

Is it possible to damage or affect the accuracy of a barrel by black nitriding it?

milo-2 It's not that I have any disdain for Cerakoting....it's just that I prefer the traditional simple black matte or blued finish. One thing I've read about the Cerakoting process is that it does add thickness and can cause stickiness and binding; another reason to avoid it in my mind. And...

www.longrangehunting.com

Barrel and Action Nitride Coating | Long Range Hunting Forum

Is it possible to damage or affect the accuracy of a barrel by black nitriding it?

I am in the process of planning a new rifle build and would like to end up with something other than a shiny SS finish. I don't care for the Ceracoat....just want to end up with a nice black matte/satin finish if possible and the Black Nitriding process appears to be that for which I am...

www.longrangehunting.com

Thanks Len! I remember reading that a while back. I searched for it a few times, but was never able to find it.

 

[HRM Johnny]

The one with 10741 rounds is just one data point, I do not know if that would be the norm or the aberration. We have not pulled any of the other treated ones. There is more coming up about to be pulled at close 6K rounds that I also mentioned.

We have barrels out there right now that have as much as 6k rounds through them that are still very competitive at 600 yards.

One of mine with over 2K rounds still hammers 600 yards. Here is a screen shot of the last targets shot at 600. The eTarget was a Shotmarker. I did not shoot this, I loaned my rifle and load to a friend to shoot in the match. This is from a 20 inch service rifle with a 4.5X March scope. My buddy out X'ed the 6mm any rifle any sight winner in the agg, 63 vs 59.

Another data point worth mentioning, one of our top shooters who won the Presidents Hundred a couple of years had one of his barrels nitrided. This one he established the precision and velocity before the treatment. Post treatment, the velocity from the same load went up almost 80 FPS. He had to back down the powder charge to get it back to the node. How did the treatment affect precision? Hard to tell, he just set a range record at the Talladega 600 match last month with the barrel. The match was held at the CMP range in Alabama.

My take right now, the longevity appears to be better, how much more? The sample is still too small to have high enough confidence level to make a statement. In a couple more years we will have over 50K rounds shot through all the treated barrels.

View attachment 166337

Did you get to 50,000 rounds? If so, what were the results? Also, thanks for sharing your experience/knowledge.

 

[Taj]

Ultimately, I think it's not worth the expense, inconvenience, and possibility of receiving a faulty treatment process, having nitride treated a few barrels. It can change headspace, and it eliminates any future rechambering on the hardened nitrided barrel.

I had one nitride barrel firecrack the bore terribly after a couple hundred rounds fired. A wasted Krieger barrel.

I was once a proponent. No more nitrided barrels for me. Just adds another process that can be done improperly, all for little potential benefit.

I was an LE field rep/ armorer instructor for a big pistol maker when they first came into the US. They used Tenifer as a finish which is a brand name for a salt bath quench nitrate finish. Never had an issue with early 9mm pistols however when the .40 S&W hit the streets issues started popping up in the form of barrel catastrophic failures. .40 pressures and of course the bore/groove diameter in the same parent barrel didn't help matters. They would never publicly admit to a problem and blamed it on ammo makers. In fact, they were one of the major reason SAAMI lowered the max chamber pressure of the .40S&W. . (from 36k to 32k if I remember right) No one else was having the same issue. A Sgt that ran the range at a very large PD in Texas was also head of IALEFI (International Law Enforcement Firearms Instructors Assoc) had several failures (with a couple of minor injuries) and sent pistols off to HG White labs for eval. It was discovered that the Tenifer process was creating microscopic "checking" in the finish and metal surface. The checking ( nitrogen embrittlement) would continue to migrate through the barrel metal until at some point in that pistols life, it would no longer proof like it did when new. A combo of this and any ammo anomaly was a recipe for a failure. The pistol maker did no additional heat treat on their barrels other than the Tenifer treatment. S&W heat treated their barrels which limited the nitrogen embrittlement migration. They were using Melonite, which is the same basic process. My point is, it's a great, very tough finish but has some draw backs if not done correctly and I believe that the parent product it is applied to, can greatly affect the performance results.

 

[bamban]

Did you get to 50,000 rounds? If so, what were the results? Also, thanks for sharing your experience/knowledge.

In a couple more years, we will have that many rounds through all the years. I will ask our equipment manager what is his best count to date. My guess we might be over my stated count. Reason, on our training week every year at Perry we burn 10k plus rounds in a week of training between 12 to 18 kids. But, almost half of the rounds are fired in rattle battle, where each 6 person team burns 384 rounds per pass. Rattle battle is really hard on the barrels. At 6 and 5, shooters dump as many rounds as they could in 50 minutes. Load count is typically 30 rounds.

The varying rounds counts before we pull out is still not known why other barrels last longer than others. So, we made a conscious decision to pull out barrels after 5K. Typical button barrels, the collective opinion across service rifle community X count at 6 diminishes between 2500 and 3K.

 

[bamban]

I was an LE field rep/ armorer instructor for a big pistol maker when they first came into the US. They used Tenifer as a finish which is a brand name for a salt bath quench nitrate finish. Never had an issue with early 9mm pistols however when the .40 S&W hit the streets issues started popping up in the form of barrel catastrophic failures. .40 pressures and of course the bore/groove diameter in the same parent barrel didn't help matters. They would never publicly admit to a problem and blamed it on ammo makers. In fact, they were one of the major reason SAAMI lowered the max chamber pressure of the .40S&W. . (from 36k to 32k if I remember right) No one else was having the same issue. A Sgt that ran the range at a very large PD in Texas was also head of IALEFI (International Law Enforcement Firearms Instructors Assoc) had several failures (with a couple of minor injuries) and sent pistols off to HG White labs for eval. It was discovered that the Tenifer process was creating microscopic "checking" in the finish and metal surface. The checking ( nitrogen embrittlement) would continue to migrate through the barrel metal until at some point in that pistols life, it would no longer proof like it did when new. A combo of this and any ammo anomaly was a recipe for a failure. The pistol maker did no additional heat treat on their barrels other than the Tenifer treatment. S&W heat treated their barrels which limited the nitrogen embrittlement migration. They were using Melonite, which is the same basic process. My point is, it's a great, very tough finish but has some draw backs if not done correctly and I believe that the parent product it is applied to, can greatly affect the performance results.

Thank you for sharing. Early on I cut the crown at straight 90. Just burnish the sharp edge of the crown. We experienced early degradation of precision. What I found the sharp 90 crown was so brittle that showed crown damage. I re-crowned the suspect barrel with a chamfer. Precision was restored.

Back in 2009 I sent out all metal parts for my M1A hunting and defense rifle, except the receiver. The place do not have FFL, still don't. Over 200 rounds in testing rifle had failure to fire. Extracted the round, chambered another, same problem. Found out the tip of the firing just sheared off. Meloniting went through and through making the tip so brittle.

Replaced firing pin with non treated and fired a few more hundreds, no issue. Rifle is truck gun when I hunted by the TexMex border, thus the reason I wanted to make sure it went bang.

 

[Taj]

Thank you for sharing. Early on I cut the crown at straight 90. Just burnish the sharp edge of the crown. We experienced early degradation of precision. What I found the sharp 90 crown was so brittle that showed crown damage. I re-crowned the suspect barrel with a chamfer. Precision was restored.

Back in 2009 I sent out all metal parts for my M1A hunting and defense rifle, except the receiver. The place do not have FFL, still don't. Over 200 rounds in testing rifle had failure to fire. Extracted the round, chambered another, same problem. Found out the tip of the firing just sheared off. Meloniting went through and through making the tip so brittle.

Replaced firing pin with non treated and fired a few more hundreds, no issue. Rifle is truck gun when I hunted by the TexMex border, thus the reason I wanted to make sure it went bang.

Bamban,

Yeah, looks like you found the issue the hard way. Small parts and sharp edges is generally where issues will show up first. I think parts that have inherited a lot of machining stress during the manufacturing process do not tolerate the process very well unless they are stress relieved before being nitrated. I have seen similar issues on both button and hammer forged barrels that aren't properly stress relieved. I have also seen failures with hardchromed bores also due to embrittlement. Robby Barkman (Robar) used to tell me that he felt that hardchrome and Tenifer/ Melonite, had the potential to be catastrophic unless done correctly. Robby is a smart SOB and cut his teeth in the aerospace coatings industry and knew of which he spoke.

 

[Bob Wright]

In the aerospace world, we used vacuum furnace nitride (nitrogen gas) on a variety of steels for wear purposes such as gear shaft journals and helical rotors. It was great for wear but due to its extremely high hardness on the surface there would be instances of damage during manufacturing or in service. We selectively treated high wear surfaces like bearing journal's or rotors using copper plate to mask. It would build on surfaces causing changes to dimensions so those required careful grinding to restore dimensions.
It's high hardness and higher brittleness was always a trade off over carburizing and toughness. I'm not surprised there are failures where sharp corners or fillet radius situations exist. Rifling would be a concern in my eyes. Any other sharp areas after nitriding are stress concentrations where cracks like to form and migrate.
There obviously is barrel applications here in this thread that work and some that don't.
YMMV.

 

[Justice1327]

I just got my 6/6.5PRC barrel from TS Customs. I plan to shoot it ~100rds, send off to 300Below and then to H&M for nitride. Hopefully it will last longer than my previous one