Cryo~??

[ELR LVR]

Air bubbles in liquid nitrogen?

Noooo from the steel

 

[butchlambert]

Noooo from the steel

Chuckle chuckle

 

[jackieschmidt]

And yet several years ago Krieger quit cryo altogether because they finally admitted it did nothing to add to the process.

There is so much misinformation on the internet about the Cryogenic treatment of barrels.

• Cryogenic processing of rifle barrels has not went away.
• All barrel steel has some amount of residual stress in it from the steel mill. How your barrel maker deals with this residual stress within the manufacturing process will determine the quality of the barrel.

I have a lot actual hands on experience with deep cryogenic treatment of barrels and stress relieving of 416 stainless. A proper deep cryogenic treatment cycle will improve a 416 stainless barrel regardless of the manufacturing process.

The cryogenic process like all other thermal operations is best performed on a cylindrical blank prior to contouring regardless of the rifling process. Cryogenic processing should be conducted prior to contouring and final lapping.

If a finished barrel is cryo treated the interior dimensions will shrink. The amount of shrinkage will vary based on a few factors.

• The amount of any remaining residual stresses in the barrel at the time of cryo
• The outside contour will effect the shrinkage areas and rates.​
• Barrels that have not been stress relieved as part of the manufacturing process will shrink more than the ones that have been subjected to a post steel mill stress relief.​
• Even with this variable shrinkage rate most people often find improvements in barrels but the only way to be for certain is to include the cryogenic process as part of the manufacturing process.​

These small dimensional changes are the reason that high end race engine shops normally perform the cryogenic processing prior to final machining on engine parts.

Cryo alone will not fully stress relieve a barrel.... it takes heat and then cryo
Think of it this way.... a NOS system will greatly enhance the performance of your hot rod but you can't run it on NOS alone.

The process is more than just dipping a barrel into liquid nitrogen... That's Bad

Stress relieving barrel material is like old people sex... It needs to happen slow and easy.

The deep cryogenic process slowly ramps the material down from ambient to -300F or colder over several hours. The temperature is held at -300F or colder for 10-24 hours to allow the material to be thoroughly soaked to complete the transition of austenite to martensite. After the soak the temperature is allowed to slowly return to ambient and this warming up process may take 24 or more hours. The last step is to temper any newly formed martensite and that is done by raising the temperature of the material and soaking it at +300F for 1-3 cycles. This is a general idea of the process. Each material and processor will have their own specific recipe.

Yes it's a lot of extra work to manufacture a cryogenic treated barrel but it's worth it.

I said in a previous post that there was a lot more to Cryo than just tossing a piece into liquid nitrogen.
With Martensitic steels such as 416, you should do a pre heat to 300 degrees F, then slowly cool. Then, you bring the barrel down to the desired Cryo temperature in gradual steps, finally reaching the liquid nitrogen temperature. This is helps for a specified time, often as much as 24 hours.
The part is then gradually allowed to Slowly reach ambient temperature, then a 300 degree F post Cryo treatment is performed for best results.
I stated that due to the sophisticated equipment involved, I doubt a lot of vendors touting Cryo Treatment were really doing much more than tossing the part into a vat of Liquid Nitrogen.
Those that say that Cryo is junk science have no idea how much it is used in manufacturing through out the world where optimum performance is desired for a given material.

 

[WSnyder]

I’m not claiming that cryo doesn’t work at all or is junk science, it’s seems to be a great addition for some industries (cutting tool industry for one). I just personally think its benefits aren’t really that applicable to what we want or need out of a barrel. Maybe the deep pocket shooters will pay for the proper process and prove me wrong but for the average guy I doubt it’ll be worth it.

 

[Rickhem]

I remember a couplea-few decades ago, that they were doing cryo treatments on high end softball bats. Supposedly it helped longevity, and kept them from getting dented up or bent as quickly. This was mostly offered by the businesses selling the bats, not the manufacturers, so it was probably just the liquid N2 dip method. After a few technical papers were published stating how it really didn't do anything for aluminum, at least not like how it helped steel, that trend went away.

 

[rjtfroggy]

There is so much misinformation on the internet about the Cryogenic treatment of barrels.

• Cryogenic processing of rifle barrels has not went away.
• All barrel steel has some amount of residual stress in it from the steel mill. How your barrel maker deals with this residual stress within the manufacturing process will determine the quality of the barrel.

I have a lot actual hands on experience with deep cryogenic treatment of barrels and stress relieving of 416 stainless. A proper deep cryogenic treatment cycle will improve a 416 stainless barrel regardless of the manufacturing process.

The cryogenic process like all other thermal operations is best performed on a cylindrical blank prior to contouring regardless of the rifling process. Cryogenic processing should be conducted prior to contouring and final lapping.

If a finished barrel is cryo treated the interior dimensions will shrink. The amount of shrinkage will vary based on a few factors.

• The amount of any remaining residual stresses in the barrel at the time of cryo
• The outside contour will effect the shrinkage areas and rates.​
• Barrels that have not been stress relieved as part of the manufacturing process will shrink more than the ones that have been subjected to a post steel mill stress relief.​
• Even with this variable shrinkage rate most people often find improvements in barrels but the only way to be for certain is to include the cryogenic process as part of the manufacturing process.​

These small dimensional changes are the reason that high end race engine shops normally perform the cryogenic processing prior to final machining on engine parts.

Cryo alone will not fully stress relieve a barrel.... it takes heat and then cryo
Think of it this way.... a NOS system will greatly enhance the performance of your hot rod but you can't run it on NOS alone.

The process is more than just dipping a barrel into liquid nitrogen... That's Bad

Stress relieving barrel material is like old people sex... It needs to happen slow and easy.

The deep cryogenic process slowly ramps the material down from ambient to -300F or colder over several hours. The temperature is held at -300F or colder for 10-24 hours to allow the material to be thoroughly soaked to complete the transition of austenite to martensite. After the soak the temperature is allowed to slowly return to ambient and this warming up process may take 24 or more hours. The last step is to temper any newly formed martensite and that is done by raising the temperature of the material and soaking it at +300F for 1-3 cycles. This is a general idea of the process. Each material and processor will have their own specific recipe.

Yes it's a lot of extra work to manufacture a cryogenic treated barrel but it's worth it.

Listen to this guy, he makes some of the best barrels out there.

 

[butchlambert]

Many years ago I chambered 10 barrels with some cryo ed. I was able to pick out which ones by the way they machined. Couldn't see that they shot better.

 

[gunsandgunsmithing]

Many years ago I chambered 10 barrels with some cryo ed. I was able to pick out which ones were by the way they machined. Couldn't see that they shot better.

I do think they machine better. The rest is yet to be determined but I can see potential benefits and no down sides other than a few dollars. I think you are right on the machining aspect though and who doesn't like that aspect of it, alone?

I do believe that it may well affect "harmonic stability". Yes, I made the term up because I don't know a better way to put it. It DOES affect harmonics though. Even if ultimate accuracy is not improved, it may hold tune better or show tune differently. Not sure if either would be good or bad because I've simply never tested with that as the goal, but I do have such a test in mind and will work on it as time allows, soon. Bottom line, never seen a down side but haven't really explored the potential upsides either...other than the better machining.

 

[butchlambert]

Mike, My nephew is the Fine Arts Director for the Wylie, Tx school system. We sent some mouth pieces for various band instruments for cryo. He thinks it works in that application.

 

[Coyotefurharvester]

I had a H&R M12 done a month ago. Weather has messed with range time. But it definitely has not been an aha moment looking at 100 yard score targets. More like a 20-30 rd group is less stringing, wind effects more predictable?

 

[jackieschmidt]

I have thought about Cryo Treating my own barrels.

We usually keep a canister of Liquid Nitrogen on hand for freeze fitting items.

But I have no way of controlling the gradual temperature drop down to the desired liquid nitrogen temp.

A friend suggested I get some dry ice and methanol, submerge the barrel in it first, which will get it half way there, then after about 3 hours place it in the liquid nitrogen for 34 hours.

Which, of course, requires an insulated container that will not shatter under the extreme low temperature, and will also keep the liquid nitrogen from evaporating before the process is finished.

When we freeze bushings to install them, we simply use an old ice chest. But the bushing only has to be submerged for about 20 minutes untill it shrinks down enough for installation.

That, and Dry ice is expensive compared to Liquid Nitrogen, not counting the cost of the methanol.

Anybody got any ideas. I would like to give it a try.

 

[Coyotefurharvester]

The company that did mine uses liquid nitrogen. They told me 24 hrs at -300 than 2 days to get back to "room temp". Suppose to be easier cleaning, better accuracy, slight velocity increase? 60 -100 dollars seems to be going rates?

 

[butchlambert]

Don't the better ones do it in a vacuum?
Do you remember the company that also shook the barrels or vibrated them? I do that every time I go to the line.

 

[gunsandgunsmithing]

Mike, My nephew is the Fine Arts Director for the Wylie, Tx school system. We sent some mouth pieces for various band instruments for cryo. He thinks it works in that application.

Well Butch, maybe they should try the rest of the instrument, as cryo'ing musical instruments for world class instrumentalists has been pretty common for several years now.
Since mouthpieces for a lot of instruments are made of plastic and wood, I do have to wonder about your mouthpiece comment. We're you trying to add something of value? If so, I missed it but that happens at times and I'm probably not smart enough to keep up with valed comments.

So please clarify...for me.

 

[butchlambert]

Well Butch, maybe they should try the rest of the instrument, as cryo'ing musical instruments for world class instrumentalists has been pretty common for several years now.
Since mouthpieces for a lot of instruments are made of plastic and wood, I do have to wonder about your mouthpiece comment. We're you trying to add something of value? If so, I missed it but that happens at times and I'm probably not smart enough to keep up with valed comments.

So please clarify...for me.

I'm not a musical person as you probably happen to be, but I thought a lot of them had brass mouth pieces. I'm not speaking of drums or pianos.

 

[ELR LVR]

I just personally think its benefits aren’t really that applicable to what we want or need out of a barrel. .

No offense but,
Have you conducted any independent testing to obtain empirical results to base your personal opinion on?
In my own personal opinion,
Anything that can be done to help with barrel accuracy "IS" what we want and need out of a barrel
Maybe not for hunting
But for everything else we plan to do.
Preventing barrel walking as it heats up is just one major benefit
A hunter may never witness this
But guys firing strings of 20 quick shots would likely pay twice the price of a custom barrel
just to get this one benefit alone.
--- I know I would
This is similar to the opinions on Lapping, it does make a difference depending on the application and the results desired

 

[a1712]

Well Butch, maybe they should try the rest of the instrument, as cryo'ing musical instruments for world class instrumentalists has been pretty common for several years now.
Since mouthpieces for a lot of instruments are made of plastic and wood, I do have to wonder about your mouthpiece comment. We're you trying to add something of value? If so, I missed it but that happens at times and I'm probably not smart enough to keep up with valed comments.

So please clarify...for me.

Trumpet, Coronet, Baritone, Trumbone, Tuba all use metal mouthpieces. Brian.

 

[ELR LVR]

I have thought about Cryo Treating my own barrels.

We usually keep a canister of Liquid Nitrogen on hand for freeze fitting items.

But I have no way of controlling the gradual temperature drop down to the desired liquid nitrogen temp.

A friend suggested I get some dry ice and methanol, submerge the barrel in it first, which will get it half way there, then after about 3 hours place it in the liquid nitrogen for 34 hours.

Which, of course, requires an insulated container that will not shatter under the extreme low temperature, and will also keep the liquid nitrogen from evaporating before the process is finished.

When we freeze bushings to install them, we simply use an old ice chest. But the bushing only has to be submerged for about 20 minutes untill it shrinks down enough for installation.

That, and Dry ice is expensive compared to Liquid Nitrogen, not counting the cost of the methanol.

Anybody got any ideas. I would like to give it a try.

Just an idea here
What if you insulated the barrel in such a way that the liquid nitrogen
Slowly is allowed to bring the barrel temp down to it's own temp.
For instance
--------------------------------------------------------------------------------------------
Putting the barrel in a pvc tube filled with water then freezing the container
so the barrel is encapsulated in ice. (plug the bore so it does not swell the barrel)
Once the barrel is then frozen in ice like a Mastodon in the Arctic
Then put the encapsulated ice barrel into the liquid nitrogen
The ice will remain frozen and it will take some time for the colder temperature of the Nitrogen to transfer over through the already cold ice, thereby then treating the barrel.
It would be similar to slowly bringing the barrel closer and closer to the nitrogen
Except in this case, it is the Nitrogen temp which is slowly getting closer and closer to the barrel until everything is at a uniform temp.

 

[338 Mollett]

Stress relieving barrel material is like old people sex... It needs to happen slow and easy.

LMAO !

 

[gunsandgunsmithing]

Just an idea here
What if you insulated the barrel in such a way that the liquid nitrogen
Slowly is allowed to bring the barrel temp down to it's own temp.
For instance
--------------------------------------------------------------------------------------------
Putting the barrel in a pvc tube filled with water then freezing the container
so the barrel is encapsulated in ice. (plug the bore so it does not swell the barrel)
Once the barrel is then frozen in ice like a Mastodon in the Arctic
Then put the encapsulated ice barrel into the liquid nitrogen
The ice will remain frozen and it will take some time for the colder temperature of the Nitrogen to transfer over through the already cold ice, thereby then treating the barrel.
It would be similar to slowly bringing the barrel closer and closer to the nitrogen
Except in this case, it is the Nitrogen temp which is slowly getting closer and closer to the barrel until everything is at a uniform temp.

Cryo is not simply dipping a bbl into liquid nitrogen, as has been implied by another poster. It is a controlled process and yes, the temp can and should be ramped down at a controlled rate. Even different alloys respond to this rate and hold time differently.
I don't see a further need to respond regarding mouthpieces. They are removable on all I've seen as well as there being woodwinds, percussion and brass instruments. I don't know but I doubt there'd be much benefit from cryo'ing a mouthpiece to either type but...maybe. That's why the term mouthpiece, IMO, was not proper, in the context of cryo benefits. I don't think a slobber piece on a musical instrument will respond much from being frozen. The other end is what makes the sound and why they are cryo'ed. Hot air has uses but not yours or mine. Lol!