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Old September 21, 2018, 09:17 AM   #1
TrueBlue711
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How does cryo affect the barrel accuracy?

So I'm checking out this company X-Caliber where they can build your barrel to your specifications. As I'm "building" it on their menu, one of the questions asked is if I wanted to use cryogenics on the barrel. What does that do to it? Is it worth it? It ups the barrel price by $80.

This is a more caliber specific question, but I'm also debating what twist rate I should go with. The barrel I'm hoping to build is for 224 Valk with the intention of long distance shooting (~1000 yards), typically using the heavier 90gr bullets. Barrel length will be 24". Twist rate options that I'm debating on are: 1:7 w/ 6 groove, 1:7 w/ 5R, 1:6.5 w/ 6 groove, and 1:6 w/ 6 groove. Is 5R rifling so much better than the 6 groove that I should go with the lesser twist rate of 1:7? Or go with a super twist rate like the 1:6.5 or 1:6 for this round?
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Old September 21, 2018, 09:59 AM   #2
Jim Watson
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Can't say about cryo, or number of grooves, but some years ago I set up a .223 for LR with the 6.5 twist recommended by Sierra for the 90 gr SMK.

With a 28" Krieger 6.5 twist and a lively disregard for published maxima, I found I could get a 90 gr to 2680 fps as needed to stay supersonic at 1000 yards. Unfortunately that heavy a load would deform enough of the SMKs in flight to make them useless. Similarly, pushing a 75 gr Amax fast enough would blow them up in midair.
Load either bullet down a bit and they were great to 600.
I tried some 80 gr Nosler and Sierra but they were not as accurate in my rifle.

For Long Range I went to the JLK VLD 90 (no longer made) and the Berger VLD 90 gr.
They held up to hot loads and shot well.

Paper ballistics say the 90 gr .224 should shoot with the 175 gr .308 to 1000 yards.
I couldn't do it on the range; I scored better with my F-T/R .308 even though the heavy bullet .223 was more accurate at midrange.

Seems most of the Valkyrie work reported in blogs and gunzines has been at the 7 twist which lets the Sierra live at 2700 fps.

Hang on, I am sure a Valkyrie enthusiast will be along presently with more current and relevant information.
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Old September 21, 2018, 10:35 AM   #3
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Cryo prolly doesn't hurt anything.
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Old September 21, 2018, 10:52 AM   #4
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Suggesst you go with it. ...

Quote:
What does that do to it? Is it worth it? It ups the barrel price by $80.
If it were mine, I would have it done and even though it doesn't entail much, it is worth the money. You already have quite an investment in this project. A little more isn't going to hurt. I have a buddy that has sent in barrels to have this done and it's my basic understanding that the process aligns the molecules, in the metal. You really should ask those folks what it does, "exactly". ….


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Old September 21, 2018, 11:16 AM   #5
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"Cryo'ing a barrel" clearly won't hurt your barrel.

There was a reasonable discussion on the AR15 forum about this, where the summary seems to be it won't hurt it, it might relieve some stress.

https://www.ar15.com/forums/ar-15/cr..._/118-521832/?

Irrespective, it **might** make a bench-rested gun a bit more accurate, but I'd be surprised if there was a significant improvement in *precision* (group size).

And if there was significant proof that it made a major difference, every rifle barrel that cost more than $200 would get that treatment from the factory automatically.
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Old September 21, 2018, 12:31 PM   #6
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I believe its Shilen that has proved to themselves its a waste of money.
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Old September 22, 2018, 03:21 PM   #7
HiBC
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Straight up: I don't have the engineering knowledge to tell you anything first hand. I can tell you what I have read.

As a retro process,for a finished barrel, I'd give it a thumbs down.I've read it has a detrimental effect on the very surface of the steel.

However,IMO,the folks at Kreiger know their way around making a barrel.

Cryo is part of their in process stress relief.Note:

IIRC Krieger produces a stress relieved ,contoured,finish bored,cryo'd ,and initially lapped barrel...very stress free,when all that is left is cut rifling and finish lapping. These processes induce little ,if any,stress.

I'm not here to bash button rifling,or argue the merits.World class barrels are button rifled.
My understanding is that button rifling must occur while the barrel is a cylindrical blank,before contouring.
The button induces stresses,and the bore is done except for finish lapping when the button passes through.

I may be wrong,but Shilen might be correct that cryo just does not fit into the button rifle process in a way that is beneficial.

That does not preclude fitting it into the cut rifled process in a beneficial way.

I'm not a barrel maker.I'm puzzling a bit about 6 grooves in a .224 barrel.It might be great,but I think Lilja does 3 grooves in a .224 barrel
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Old September 22, 2018, 03:28 PM   #8
RC20
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I think all it is is a spin thing that claims benefits that are not there.

Sort of, we are more special because we X.

Krieger indeed makes good rifle barrels, but so does Shilen etc.

As it does not harm its just spin but of no benefit and I would not pay 5 cents extra for it.
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Old September 22, 2018, 03:50 PM   #9
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We do agree fine barrels are made by the different processes. And its not worth arguing.

I'd buy a barrel from cut,button,or hammer forged. I have,and all have served well.

I don't fancy myself a good enough shot to worry about it much.

I used to be loyal to Douglas. They never disappointed me. I got good,accurate barrels. Some folks don't find them excoiting. I've tried Wilson,Badger, Northern Competition (Badger)Shilen,Douglas, Lilja Lothar Walther,Daniel Defense,and Krieger.

All of them make fine barrels.

If I was building something special,I'd probably go Krieger.Or maybe I'd try my first Obermeyer. I've slowed down on rifle projects. Not sure I need anything
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Old September 22, 2018, 06:40 PM   #10
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I suspect most barrel makers send out their cryo work and make very little profit on it. I would probably rely on the barrel maker's advice regarding cryo treatment.

I can't speak from experience, but my understanding is that the more a barrel requires straightening during the manufacturing process, the more it can benefit from cryo. From what I've read, barrels that were straightened are the ones that generally walk shots as they heat up. And cryo supposedly relieves the stress created during straightening, minimizing the warm barrel walking. But that's just what I've read.
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Old September 22, 2018, 06:41 PM   #11
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Cryogenic treatment is supposed to provide the benefits of stress-relieving and normalizing all in one step, just much faster than traditional methods (oven). People talking it up are mainly the people doing the treatment. I have never seen anything credible that shows it as better than oven normalizing or stress-relieving. Cost-wise, it is more expensive than oven stress-relieving. And since most barrel-makers stress-relieve their barrels, it is a question of whether or not you believe the sellers.
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Old September 23, 2018, 09:17 AM   #12
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Quote:
And cryo supposedly relieves the stress created during straightening, minimizing the warm barrel walking. But that's just what I've read.
I don't know that any after market barrel makers straighten barrels. If they are not straight when drilled or finished they get dumped.

Savage does still straighten barrels, so maybe a nit noid that they are not a barrel maker that you can buy one from unless you buy the whole rifle.
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Old September 23, 2018, 11:59 AM   #13
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Cryogenics is an unproven stress relief method. Doesn't do anything one way or the other. If it did, all manufacturers would be using it.
The Cryogenic Institute of New England, Inc. charges $50 plus shipping for a rifle barrel so it's not terribly expensive. Dunno what "All pricing subject to a $75.00 minimum lot charge." means. They claim increased accuracy just by doing it. That screams BS marketing to me.
Mind you, the .224 Valkyrie is yet another answer to an unasked question. However, long distance shooting requires heavy bullets. So the rifling twist has to be suitable. That's far more important than deep freezing the barrel.
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Old September 23, 2018, 05:22 PM   #14
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Back in the lat 90s, Kevin Thomas, who was one of the balisticians at Sierra bullets did a controlled test, comparing two barrels from the same source, one had been cryo treated and one hadn't It was published in Precision Shooting magazine, back when that was still a thing. He could see no difference in accuracy but maybe a slightly longer useful life.

Shilen and Lilja both say it doesn't really do anything.

http://riflebarrels.com/support/faq/
http://www.shilen.com/faq.html
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