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Steel cased vs brass cased an interesting read.

20K views 47 replies 29 participants last post by  Texpat 
#1 ·
#7 ·
Bi-metal jackets don't just cause accelerated wear with high rates of fire. Shooting Wolf and Brown Bear almost exclusively over the life of my SLR-106 has resulted in the barrel degrading from 2 MOA performance with Prvi Partizan 75gr match to 6+ MOA in less than 7000 rounds.

I wish like hell I'd known this years ago. Replacing the barrel on an SLR-106 is a major pain in the ass and is going to be $$$.
 
#9 ·
The test used American-made barrels only.

It might be American-made barrels are made for copper jacketed bullets typically found in brass-cased ammo and cannot stand up to the bimetal jacketed bullets typically found in steel-cased ammo.

It might be that Russian-made barrels are made for bimetal jacketed bullets, so this test may not be relevant to AK rifles.
 
#11 ·
American-made barrels in this case were both button rifled/chrome lined and (one of the American barrels used was) cold hammer forged/chrome lined, which is the same manufacturing process used by Russia and the former soviet bloc countries to make AK barrels. All tested barrels, including the cold hammer forged barrel, showed nearly identical wear patterns and accuracy results- that is to say, all the barrels used with bimetal jacketed bullets were shot out around 6k rounds, to the point of keyholing rounds. A button rifled, chrome-lined barrel used with copper jacketed bullets survived the 10,000 rounds test still producing similar accuracy to the start of the test and showing measurements on a throat gauge indicating that it still had some thousands of rounds of life left, despite the rapid fire abuse. My cold hammer forged SLR-106 barrel hasn't shown signs of keyholing, but accuracy loss is significant and appears consistent with the degradation recorded on the charts in the test. (several of the images are actually multi-image slideshows showing data for multiple ammunition types)

Without further testing, all we can do is speculate. I do know my SLR-106FR barrel's throat looks like it has a lot of wear for only 6-7k rounds and that it now shoots 6-7+MOA, with the same ammo (75gr Wolf gold made by Prvi Partizan) from the same lot I bought when the rifle was new, that it used to shoot close to 2 MOA with. That same ammo does still shoot 2 MOA out of my pencil barrel 16" AR-15. I shot Russian-made Wolf and Brown Bear ammo almost exclusively out of the SLR-106FR at a firing schedule varying from 3k-500 rounds a year over the course of about 4 years, mostly at competitions and informal practice sessions where both slow and rapid fire were used (no magazine dumps- ever. Just rapid 2s, 3s, and 4s, per target for about 30-50 rounds over the course of a few minutes as in 3-gun, etc)

I have one slight bt of heartburn with this article in that it keeps referring to steel case vs. brass case in the title and a lot of the statements
The Lucky Gunner article refers to steel case and brass case because that's what the author originally set out to examine the difference between. The phenomenon with the bimetal jacketed bullets was an unexpected discovery. The case material does not play into barrel wear at all, only the jacket material.

Evidence seems to suggest, at least with .223, that the difference in wear between bimetal and copper jackets is significant and appears to become more significant the more rapid fire is used. Without more detailed knowledge of the subject however, there is still room for the Russian powders used to be at fault, or at least a factor. All that can be stated now is that current Russian-made steel cased .223 ammunition seems to cause greatly accelerated throat erosion and premature loss of accuracy compared to typical brass-cased .223 ammunition.

IIRC, there exist on the internet documents of US military testing of steel jacketed .30 caliber bullets, testing with said bullets using barrels with various different linings (chrome, etc). That information may offer some clues to help roughly extrapolate wear performance in a slower .30 caliber rifle like a 7.62x39 AKM.

Based on my experience and what the gathered information seems to indicate, I suggest users avoid using bimetal jacketed .223 ammunition in rifles that can't easily and cheaply have their barrels replaced.
 
#10 ·
I have one slight bt of heartburn with this article in that it keeps referring to steel case vs. brass case in the title and a lot of the statements. The real culprit is bi-metal jackets vs. copper jackets as the article does make fairly clear. For AK's, they are designed around steel cased ammo and steel cases are probably best ion them, although I do shoot a lot of brass cased Yugo ammo. What would really be nice for AK enthusiasts would be steel cased ammo with copper jacketed bullets. I think we may have this for 5.45 and 7.62x39 now with Hornaday ammo. However, at $0.40 and $0.60 per round they are pricey especially the 7.62x39 since fully reloadable brass cased 7.62x39 can be had for as low as $0.50 per round or less.

MDI
 
#12 · (Edited)
Looks like Red Army Standard in Ukraine is making steel cased ammunition with copper only jackets. Non-Magnetic
I ordered some to try out. It could be a good solution between less expensive steel case, and more expensive brass case.

I have only found it in x39 so far, but I would imagine if it sells good they will keep making it.

180 round range pack - 7.62x39 FMJ Copper Jacket Non-magnetic 123 Grain Bullet Steel Case Non-Corrosive Ammo - Red Army Standard - AM1925A | SGAmmo.com

http://www.sgammo.com/product/red-a...pper-jacket-non-magnetic-123-grain-bullet-ste
 
#13 ·
Looks like Red Army Standard in Ukraine is making steel cased ammunition with copper only jackets. Non-Magnetic
I ordered some to try out. It could be a good solution between less expensive steel case, and more expensive brass case.

I have only found it in x39 so far, but I would imagine if it sells good they will keep making it.

180 round range pack - 7.62x39 FMJ Copper Jacket Non-magnetic 123 Grain Bullet Steel Case Non-Corrosive Ammo - Red Army Standard - AM1925A | SGAmmo.com

1080 Round Case - 7.62x39 FMJ Copper Jacket Non-magnetic 123 Grain Bullet Steel Case Non-Corrosive Ammo - Red Army Standard - AM1925B | SGAmmo.com
Cool! Nice to see this. If I had a 7.62x39, that's what I'd buy.
 
#15 ·
Based on Aries14482's observations, this seems to also present a problem for 5.45. Especially once the surplus becomes harder to obtain, as it eventually must. Unless the manufacturers change their bullet designs, the majority of commercial ammo has the bimetal jackets. Not as big a problem for those with readily replaceable AR15 5.45x39 barrels, but the difficulty of swapping out AK barrels poses even more of a problem for 5.45x39 AK owners as it does 5.56x45. Unless the extra 200 ft/sec or so difference in velocity or some difference in bullet design makes a significant difference in wear between the two?

I've kept an eye out this year for further observations about this, but haven't seen any, much less any tests of barrel wear from commercial 5.45. Anyone know of any?
 
#16 ·
What are the numbers in an AK were looking at?

Im seeing 6k rounds for steel and ill guess 14k rounds for copper in the life of an AK.

Steel is about 22 cpr brass is 28 cpr. A difference of 6 cpr, at 8000 rounds berween steel and brass used barrels
That comes out to $480 saved over using steel vs brass. So basically the price of a new wasr. How much does it cost to replace the barrel, $200 or $250? Depending on how you want to approach this, you may be fine shooting steel.
 
#19 ·
It's looking more to me like 5-6k for steel jacketed rounds vs 25k+ for copper jacketed 5.56, if Redman's round count post was anything to go by. 7.62x39 could be wildly different. There just really hasn't been enough testing to get a good idea because who keeps round counts, ammo types used, and meticulous accuracy data over the lifetime of an AK?
 
#17 ·
It also very much depends on the cartridge. Out of 5.56, 7.62x39, and 5.45x39; 5.56 will wear a barrel the fastest with 5.45 not far behind. Pressure factors in majorly. 5.56 is a pretty brutal cartridge and especially with m855 and the new m855a1. They wear on the entire gun pretty rapidly because they have a very extreme pressure curve. There have been plenty of estimates thrown out, but there are a large quantity of variables that come into play as well.
 
#22 ·
I was just pointing out that its difficult to even give an estimate due to the massive amount of variations. There have been several members here who have reported pretty serious loss of accuracy with Arsenal 106's after only 6k-7k rounds. As far as replacing a barrel, that would depends. Let's say worst case scenario you pay the ~$200 K-var wants for one of Arsenal's barrels and pay a smith to install it. I've seen estimates sit around $250-300 for barrel swaps I think. So you'd be looking at close to $500 or so. The savings on 7.62x39 would be substantial considering they can get a pretty serious amount of rounds down them before wear gets bad.
 
#20 ·
I really liked the article and the info provided. I would have liked to see 3 brass cased/copper jacketed US flavors used as well and not just Federal. Also curious about a 55gr (M193) vs 62gr (M855) comparison.

I would love to see this kind of test done with 7,62 & 5,45 AKs as well. Big money in that kind of testing though.
 
#28 ·
Dont over think it. They shot 10k rounds in a day. Until you start doing that or laying down some serious suppressive fire you won't see that type of wear. Even standard lead fmj ammo will do that in prolonged fire. Which is why a lot of machine guns have quick change barrels. The rate they shoot at they wear out barrels fast from the heat generated by soft bullets

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#33 · (Edited)
If you look at the info in the first post, the accelerated barrel wear was somewhat random with the hotter propellants, with some barrels approaching the barrel life of those shot with cooler propellants and some "dying" much sooner. The cooler propellants showed much more predictable barrel life, as well as consistently better barrel life. This phenomena would explain why some people report many rounds with no issues and some, like me, report early barrel "death."

If it is a powder issue, it means that barrel wear issues could be limited to Russian .223 only, or perhaps even just to certain lots.

Anyway, this does seem to provide conclusive evidence that the issue is NOT the bi-metal bullets, but the powder.
 
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