Salt-Bath Nitriding for Rifle Barrels
 

Has anybody had any experience with a rifle barrel treated with this method? If so, where did you have it done?

Apparently, salt-bath nitriding a rifle barrel considerably prolongs it's life.

maybe in pistol barrels and other low pressure barrels but given the heat required i would steer clear of it until further testing can prove conclusively that you wont blow yourself to bits.if it was so great the benchers and f classers would be all over it like a large kid on a smarty.

Sounds like Hot Bath Bluing, to me. :confused:

Grizz

Glock and some motor companies have been using the similar process for years and years.

maybe josh but we are talking about hardening and that requires temps that change heat treats,sometimes to the point of overhardening and embrittlement.like i said in blowback systems,etc this may be fine but in 60000+pressures are u willing to risk your life?any of you engineers want to comment?

I guess if its done after the fact, to an unknown alloy you could have problems. However if it is done when the part is being made, with all things known and controled I think it could be a good thing.

When we picked up the Rock Creek Barrel line we met with Joel Kendrick from MMI Trutec, Salt Bath Nitriding @ the Rock Creek / Seekins / MMI booth. He has a Bat action which was completely done and very slick!! The barrel was also done and he mentioned super extended barrel life.

We were talking about using this process with the New Carbon fiber barrels but we still have some logistical issues to deal with. More great stuff.

A shop in Edmonton also does some salt bath nitriting so we will be trying this out on some custom dies and possibly some of our brakes.

Here is a link...



http://www.youtube.com/watch?v=jiegZyhd5l0&feature=fvw

We nitride objects that need wear resistance by an outfit out of Edmonton. The case depth is anywhere from 0.005 to 0.020" thick. Nitriding does three things - it significantly increases wear resistance, improves fatigue and reduces corrosion. Win, win, win. This would greatly extend the life of the barrel, reduce throat erosion and would be especially advantageous to competitive shooters or overbore cartridges. If you wanted to be extra cautious you could just liquid nitride the bore where stress is lowest. (note we are not talking contact stress here)

Talk to the specialists to determine what type of nitriding would best suite a rifle barrel and tell them your application.

The barrel needs to be broke in before nitriding but after treatment the bore has a very long life and great corrosion resistance.

You might want to check your theory. Stress is highest in I.D. of the tube / barrel. Lowest at the OD. The stress decreases as you move outward through the thickness of the tube.

Sorry for bumping this necro thread...

In the last 6 years has anyone gained any experience in Nitriding rifle barrels?

No experience in rifle barrels, but we Liquid Nitride 4140 all the time for downhole tools. The temperature is hot, but it does not get near hot enough to anneal or to change the phase of the metal causing a change in strength. If it goes in at a YS 110ksi, it comes out at that. We run this stuff to 90% of yield, no issues.

So my Engineering side says sure why won't it work, my farm boy side says "give'er" But I'm far from a gunsmith, so in the end would ask for their experiences. Once thing to keep in mind, it's only .004" - 006" deep. Gas Nitriding is a bit more, maybe .010" But any sharp thin edges can be prone to chip or break due to being hardened completely through......

That's my two bits.....

I wouldn't be surprised if you called up the guys at Thermex in Edmonton that they'd likely have done a few and could provide some feedback.

Had a .338 AI barrel done increased the pressures dangerously, had some brass separation with loads that after I went back to a standard S.S. barrel never another pressure issue. Maybe with pistols or light calibers but I would not recommend anything in the magnum area unless your a gambler.

A friend is currently testing a salt bath nitride barrel he had done at Thermex. I believe it is a 6.5 Grendel. The cut rifled blank was chambered and nitride’d (bore and exterior). Initial clean-up required the use of bore paste as it was difficult to remove the residue. Carefull measurements were made ... and shooting commenced. Initial groups were mid-threes @ 100M. I doubt there will be any shooting again until spring. He will be tracking throat erosion as the count mounts.

Very interesting!!