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  1. #1
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    Jul 2011
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    Default Chrome Lined barrel vs Non

    Seems a lot of people take high stock into owning an AK with a chrome lined barrel and pay more than $200-$400 more for a rifle with a chrome lined barrel. This is inherently thought of as a need for a longer lasting barrel when you throw a lot of rounds through. Some of the reasons I see US importers may throw the non chromed barrel on is because of cost, time and demand. Then I recall seeing why the Germans chose to put a non chrome lined barrel on the HK416. They simply stated it was more accurate even though it had a shorter life span. Then it was obvious and sitting right in front of me, literally. Few years back I was really into long range whacking of prairie dogs and antelope. I have a Remington 700 Sendaro VS SF in a 7mmSTW (Shooting Times Western). Those unfamiliar with this cartridge it is not the size of a 7MM Mag. It is an 8mm MAG round necked down to a 7mm. Looks about the size of a 300 Ultra in length, girth and gains of powder in the case. The shoulder and caliber is what sets the brass apart.
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    Now the reason the caliber is so important in this post is the fact of the blistering speed and pressure put on the barrel of this rifle.
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    The velocity ballistics on 7.62x39
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    With my reloads I was shooting 120-140gr ballistic tips pushing near 4400FPS for velocity at the muzzle through mine. Forgive the basic data, if need be I can dig out my Nightforce XBAL program to verify data. But at near twice the velocity of what the 7.62x39 will do at any distance you can imagine how hard this is on the bore of this rifle. This is also part of the reason Remington no longer offers this chamber due to the shortened life span on the rifle. But the is a way you can extend the life on the barrel in which I did. I took my rifle to my local sporting goods store and had it sent to a similar place to this. http://www.300below.com/firearms-cryo-barrel/ The service charge at the time (2002) was $60 which I do not believe has changed much. Total with shipping and tax was about $90. Did it make a difference in accuracy? You bet it did. It was about as big of improvement as going from store bought ammo to loading my own. I do not consider myself a great shooter capable of amazing feats but here was the progression. Store bought ammo gave me a shot group firing 20rds of the size of a baseball at my 135yd Zero (for this setup). Same distance with hand loads I could tighten up a 20rd group to a golf ball. After I got it back from Cryo treatment it went to the size of a small pop bottle cap. I was so impressed we were shooting plastic bottle caps off the top of the target. As far as longevity I still own this rifle and regret selling it's unfired twin. I have shot easily more than 2000rds which in my opinion to get 1000rds is very good quality.

    The 7.62x39 round fired through an AK is notorious for poor accuracy so is it possible that someone thought Americans like to hit what they aim for? Is is possible that this was their intent and not just cost savings? Regardless, I believe you can get a much better AK with a non Chrome lined barrel by paying the lesser price and have it sent for cryo treatment. Two things I believe it will accomplish, a far more accurate rifle and just as long or longer life than a chrome lined bore. So long as you do not have one with a key holing issue out of the box (which is a manufacturing defect) , I think it is well worth having this done with the rifle you plan on shooting on a regular basis.

    Again this is only my personal hypothesis, has anyone done this already or thoughts?
    Last edited by Fosgate5; 09-18-2011 at 08:50 PM.

  2. #2
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    Nov 2010
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    Default

    I thought the crome lined barrels were for corosion pertection. I never thought of the accuracy think. I have a 47 and 74. 74 is crome lined but I don't realize much more accuracy......
    NRA LIFE MEMBER
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  3. #3
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    Apr 2008
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    Default

    Unlined barrels are more accurate. Chroming was for corrosion.

  4. #4
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    Jul 2011
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    Default

    The benefits of chrome lined. http://cheaperthandirt.com/blog/?p=2678

  5. #5
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    Aug 2011
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    Default

    Quote Originally Posted by Fosgate5 View Post
    The benefits of chrome lined. http://cheaperthandirt.com/blog/?p=2678
    Good article, thanks for linking it. I think it sums up the advantages/disadvantages of each very nicely. I seem to remember reading somewhere that very high velocity cartridges like the one the original poster mentioned, and others like .22-250 are more prone to throat erosion than most of the common military calibers many of us shoot, but even then, it would take thousands of rounds to notice any significant impact on accuracy. Bottom line for most people, chromed or un-chromed probably is not going to make a whole heck of a lot of difference in either accuracy or bore life.

  6. #6
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    Dec 1969
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    Default

    Thanks for the information!

  7. #7
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    Dec 1969
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    Oldsmar, FL (Tampa Bay)
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    Chrome plating isn't used for match barrels because it adds another possible source of uncertainty to barrel dimensions. It's used in full auto weapons to cut fouling and extend life, and in the Warsaw pact firearms because of the use of corrosive ammunition.

    Cryogenic stress relief does little or nothing to quality barrels. Better look elsewhere for the reason for your accuracy improvement.

    Lilja Precision barrels:

    Q. What is your opinion of the deep cryogenic processing of barrels?

    A. The cryogenic treating of barrels at a temperature of -300 degrees below zero has been a hot topic of discussion lately. Our short answer is that it will not harm your barrel but we are not completely convinced of all of the benefits claimed by some. The only benefits that we feel are likely to result from the treatment are possibly a longer barrel life and a slight increase in machinability.

    Claims for increased accuracy through stress relief are not founded in our opinion. When barrels are button rifled no material is removed, it is just displaced. This causes stresses to be formed in the steel. If these stresses are not removed problems will result. These negative conditions include warping of the barrel during other machining operations, an increase in the bore diameter towards the muzzle end of the barrel during the contouring phase, and in the extreme, lengthwise splitting of the barrel. Also, if there are stresses remaining in the barrel they can be slowly released as a barrel warms up during firing. This causes the barrel to actually move during the course of shooting, causing inaccuracy.

    In our testing we have found that the only effective means to completely remove the types of stresses introduced during rifling are with conventional heat treating using elevated temperatures. The -300 degree treatment alone will not remove these stresses. We have been told by a knowledgeable metallurgist that the deep cold treatment will, at best, remove up to 6% of the remaining stresses in the type of steel used for rifle barrels. The key words here are remaining stresses. In other words if the barrel was not stress relieved conventionally, then only 6% of the original stress will be removed. If the barrel has been treated conventionally with heat and then brought through the -300 degree cycle, up to 6% of any remaining stresses could be removed by the cold treatment. We do know through our testing that the cold treatment alone will not remove any significant amount of stress and that the problems outlined above concerning stress will remain in the barrel.

    So, because of the very limited amount of stress that could be removed with the cold treatment (if the barrel has been properly stress relieved with heat as our barrels are) we do not believe that there can be much if any accuracy benefit to the -300 degree treatment of our barrels. It is for these reasons that we feel the cold process has very little potential for increasing the accuracy of our barrels. In our opinion, other than the removal of these stresses, there are no other mechanical factors involved that could benefit accuracy in a rifle barrel, resulting from a heat treating operation, either hot or cold.

    For reasons not completely understood however there may be an increase in the wear resistance of the steel. This type of wear however does not contribute greatly to barrel erosion. We invite you to read our comments on this type of barrel wear in the question regarding the use of moly coated bullets.

    Another possible side benefit to the freezing process is a slight increase in its machinability.

    Post Script: Since I originally wrote this an excellent article by Kevin Thomas of Sierra Bullets was printed in the September, 1998 issue of Precision Shooting magazine. Mr. Thomas found, in a controlled test, that there was little benefit to deep freezing match grade barrels. He could see no difference in accuracy but probably a slight increase in useful life. I would encourage anyone interested in this subject to take a look at this article.
    I swear by Jupiter Optimus Maximus .... in the army of the consul Lucius Quinctius Cincinnatus and for 10 miles around it I will not steal anything worth more than a sestertius in any one day.

  8. #8
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    Dec 1969
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    Iowa
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    There are a lot of factors that hamper the potential accuracy of the AK. I'd say quality of ammo and the long-stroke gas piston are more significant ones that a chromed bore.

    I like chrome because it's easy to clean. And the original AK-47 specs call for a chrome-lined barrel.

  9. #9
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    Central east missouri
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    This is an excellent useful thread. Thanks for the info !!!!
    I would like to die peacefully in my sleep like my grandfather . Not yelling and screaming in agony like the passengers in his car.

  10. #10
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    Oct 2009
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    Central east missouri
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    To me just dont abuse your rifles. I have my tabuk sniper wich is acurate with Lapua or other quality rounds. I do my three shots and let her cool . With the thin barrel anything beyond three shots goes wild anyhow. Im still breaking in the non chromed barrel .Doesnt even have 300 rounds down it. I carefully clean it .I see more damage from cleaning than shooting . I saw a vendor at a gunshow cleaning a mosin sniper from the muzle using the factory gunrod and antiquated cleaning kit and scrubbing like a maniac !!! I found that mor disturbing than what goes down the pipe.
    I would like to die peacefully in my sleep like my grandfather . Not yelling and screaming in agony like the passengers in his car.

  11. #11

    Default

    My Question on The Whole Chrome lined / Non- Chrome lined Barrel Bore Issue is ? Does Chrome lining Benefit Functioning Of a Rifle Be itan Ak- or AR When Using The Russian Non -BRass Cased Ammo ? Steel cased & poly/ zinc/ Lacque rCoated or Copper washed Ammo ? Or Does it Not make any difference at all ? I know that Chroming prevents Rust From Moisture & Corrosive ammo and Barrel erosion from Hot/ High velocity Ammo ! I also Understand that There is an expansion Difference Between Brass cased Ammo and The Steel cased Russian Stuff as Steel being harder than brass Does'nt expand / deform as readily as the brass casings do ! I am asking about this Because I may get a .223 Soon and Though I have About 1000-1300 rounds of Brass cased ammo for That Newer .223 ammo purchases Will most likely be steel cased So If Chroming works better with Steel cases It might be worth the extra $ ? Thanks and Ciao y'all !!!!!

  12. #12
    Join Date
    Jul 2011
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    337

    Default

    Quote Originally Posted by bigtoxy69 View Post
    My Question on The Whole Chrome lined / Non- Chrome lined Barrel Bore Issue is ? Does Chrome lining Benefit Functioning Of a Rifle Be itan Ak- or AR When Using The Russian Non -BRass Cased Ammo ? Steel cased & poly/ zinc/ Lacque rCoated or Copper washed Ammo ? Or Does it Not make any difference at all ? I know that Chroming prevents Rust From Moisture & Corrosive ammo and Barrel erosion from Hot/ High velocity Ammo ! I also Understand that There is an expansion Difference Between Brass cased Ammo and The Steel cased Russian Stuff as Steel being harder than brass Does'nt expand / deform as readily as the brass casings do ! I am asking about this Because I may get a .223 Soon and Though I have About 1000-1300 rounds of Brass cased ammo for That Newer .223 ammo purchases Will most likely be steel cased So If Chroming works better with Steel cases It might be worth the extra $ ? Thanks and Ciao y'all !!!!!
    Chrome lined benefits rapid fire and cleaning. I think this might answer the question you are implying. http://www.youtube.com/user/Sturmgew...24/P5ZB3UfG960

  13. #13

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    will check it out and thanks BTW!!!!

  14. #14

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    I Watched The Video link you mentioned ! And it pretty much rehashed what you , I and the other members said ! what I get out of This is 1. Clean Often & correctly Chrome or Not & Check for Extraction Problems with Wolf ammo if Using shorter Than 20 inch barrels ? and Try a few Boxes first before Buying Wolf .223 buy the case ? So in Conclusion when I end up with a .223 semiauto Rifle If it's from The Ar-15 camp will Probably Go Stainless if I can afford it ? and again thanks and Have a Good day everyone !!!!!!

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