Remember a few years ago, when everybody was cryo'ing everything? What's the scoop, now that we've had a few years to get in some real world experience with cryo'ed rifles? Is it really worth it? Are any of the marvelous accuracy
claims that were originally made actually true?

R-WEST

Like most things that were too good to be true, it was too good to be true.

I cryo'ed lots of barrels and some benefitted more'n others. None were adversely affected.

For my uses, I cryo'ed any barrel I was going to shoot hot. That is, high volume varmint barrels (usually factory) and match barrels for highpower. I needed barrels to shoot to the same POI when hot, cold, heating or cooling and cryo did that for me. It did NOT decrease group size or bore roughness, nor make cleaning easier or any number of ridiculous claims seen in advertizing. It saved me from having to chuck some factory varmint barrels that would walk all over creation when heating or cooling, and if that problem arose tomorrow, I'd cryo another one.

I've never seen an improperly cryo'ed barrel but I understand it can happen.

HTH

Redial

If you review all of the empirical evidence you will find that cryogenic treatment imparts a significant amount of wear resistance to most steel and thus increases the useful accuracy life of a barrel, especially in the throat.

On the other hand, on balance, it apparently improves accuracy only nominally, if at all. This is not to say that individual firearms will not, on occasion, show marked improvement. But significant improvement seems to be a hit and miss proposition [no pun intended].

Jordan

Precision Shooting made a test cryo/no cryo a couple of years back. The evidence for any improvement in accuracy was inconclusive.

Seems though, that in terms of machining, there may be advantages to cryo treatment.
- mike

I have cryo'd a number of barrels and saw no improvement in accuracy. As said it did no harm that I could see. I could wave a dead cat over the barrels and it would likely not improve accuracy nor would it do any harm. It would, however, be a lot cheaper, given the cost of cats. If I am going to pay some of my money or my customers money for a service, I want some evidence that it is worth doing, not that it doesn't do any damage.

Isn't the primary benefit of cryo, as redial says, to stress-relieve the steel so that it doesn't walk as it heats?

If it works, that would be a huge benefit. How many barrels do we all have that change point of impact once they heat up?

The idea is to stress relieve the metal. Moving points of impact can be a cause of a lot of other things than stress. And most of the time it relates to contact somewhere in the stock or an uneven contact at the action.\

Any good barrel maker stress relieves the barrel before it is sent out to the customer. It is normally done with heat although Krieger is using cryo in his plant. Some machining processes may induce stress back into the barrel but fitting it to an action certainly doesn't.

[ 10-29-2003, 03:28: Message edited by: Customstox ]

I enjoy the effects of cryo certainly, but my anecdotal evidence is somewhat at odds with how the slide-rule guys understand metallurgy.

They explain that the metal changes in the process between austensite and martensite (sp? of either!) and that no stress relieving could be taking place molecularly! OK, fine. I don't really care how it stabilizes the barrel, only that it does!

No, it didn't improve accuracy and no, it's not necessary or advantageous for most applications. For barrel-burners like me, it has some merit. YMMV.

Cheers!

Redial

There was a long discussion on cryo which I was involved in ,you could do a search. Putting aside the hype - at this point in time the only proven use of cryo is to reduce retained austenite which you don't expect in barrels anyway.Stress relief ? if you look in a metallurgy book under stress relief you will find a comment like 'HEATING between 700 and 1100 F'.Improve wear resistance ?nonsense.But what do I know I'm only a metallurgist, magicians can do anything.