Cryogenic treatments of rifle barrels

[Ol' Red]

Cryo treatment is for stress relief. This is more so effecting the machining process from what I seemed to understand, and has the benefit of making the grains or microstructure more uniform.

Nitriding is just a surface treatment that helps with wear. These are two different things that are not interchangeable.

If anyone is interested, nitriding is its own thread topic by itself. There's different processes, and honestly, I shoot in pro circles, and I'm not aware of anyone notable putting nitride and precision shooting together.
I would do research on each process and ask the person who's doing it how they do it before committing to buying.

In any case, despite the advertised wear resistance, what nitriding does NOT help with is micro cracking in the throat.

100 percent correct. I did not mean to sidetrack this thread by mentioning nitriding. That's why I said "I went the opposite way." Are there any of the shooters in your pro circle that have used cryo treatment on their barrels, and have they noted an increase in accuracy?

 

[Justice1327]

"Cryo treatment is for stress relief. This is more so effecting the machining process from what I seemed to understand, and has the benefit of making the grains or microstructure more uniform."

This was my understanding and why I want to get it done before I have any milling/drilling done.
But I have never done either so I am all ears.

 

[david205]

1. Cryo and heat treatment are two different things. Heat treatment is performed well above 1000 deg f.
2. Indeed, barrels all have a heat treatment that determines their mechanical properties. Better barrels, better heat treatment.
3. Barrels are bored after heat treatment so the bore will have residual stresses not there at the time of the heat treat.
4 Cryo treatment does not try to replace heat treatment or do the same thing as heat treatment (unless the company offering it also offers snake oil).
5. Cryo treatment is mostly advocated by those that sell it.
6. The benefits of Cryo treatment are vague--moving of alloying atom along grain boundaries or similar but usually written in a way that sounds like things end up more homogeneous.
7. I'm on the fence. My initial thoughts are skepticism as steel properties are generally considered stable below 1200 F or so. As things get colder, it is harder to move things around. Many Steels loses ductility and become brittle at very cold temperatures (nil-ductility transition) and this isn't a state where I would expect intergrannular changes to take place. I'll keep reading but for not I'm not spending money on it.

David.

 

[HARPERC]

Some very good barrel makers out there these days. I've tried cryo when it was being pushed a bit, but decided with top grade barrels if there was a difference I couldn't realize it.

YMMV, but invest in quality, I don't think it adds, doesn't hurt.