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View Full Version : Excellent Report on AR15 wear & tear over 10k rounds


Bartholomew Roberts
January 10, 2013, 08:12 AM
http://www.luckygunner.com/labs/brass-vs-steel-cased-ammo/

The authors of this report took 4 identical Bushmaster MOE rifles and fed them each a different brand of ammo for 10k rounds to note changes in wear and tear. The whole report is an excellent read; but some of the more interesting points to me were:

1. Russian ammo does cause additional wear - not so much from the steel cases but from the bimetal jackets. Barrels shot out roughly twice as fast and reliability worsened earlier.

2. An excellent example of how a midlength functions to take ammo that was marginal in a carbine and shoot it reliably from the midlength.

3. Those cheap components that look just like what comes in a Colt but cost half as much? They matter and affect reliability.

Great read and well worth your time.

Alabama Shooter
January 10, 2013, 08:31 AM
Wow, what a test. While it is a small sample it seems to confirm what many people have been saying all along about various types of ammo. Thanks for posting this.

madcratebuilder
January 10, 2013, 09:14 AM
Great link, thanks!

The throat erosion and barrel wear was a wake up.

Bartholomew Roberts
January 10, 2013, 09:25 AM
Yes, that surprised me as well though it makes perfect sense when you think about it. It basically means that every case of Russian 5.56 with bimetal jackets is about $50 more expensive than you think due to increased barrel wear.

Alabama Shooter
January 10, 2013, 10:03 AM
It is less money to shoot the cheap stuff in the long run but you have to wonder if it is worth it? I would rather retain the accuracy and consistency of pressure loads over the service life of the rifle than save a few bucks shooting.

If god forbid there is ever another ban than we need to think what will provide the best long term results for you.

runningbear
January 10, 2013, 02:55 PM
Great report lots of information. Myself I have never shot any Russian Ammo. in my ARs and won't ever. I do shoot it in my AKs. I do understand with the way things are heading the Russian Ammo. gets bought because first off it's now or it was easy to find and prices were good. I think soon the Russian Ammo. will be harder to come by also prices will climb up. I hope I am wrong. I did find some copper case and copper coated lead core bullet Win. 7.69x39 and shot it in one of my AKs and if I could afford it I would shoot it all the time over the Russian Ammo.:)

slim9300
January 11, 2013, 01:47 AM
Great link!


Sent from my iPhone using Tapatalk

Adamantium
January 11, 2013, 12:53 PM
3. Those cheap components that look just like what comes in a Colt but cost half as much? They matter and affect reliability.

Two mentions of Colt in that article...

Couple this with the .058″ gas port used on the Bushmaster rifles – about the same as a Colt 6920 with a 16″ barrel, and just about the smallest gas port you’ll see on any 16″ carbine AR-15, and you’re bound to encounter problems. The Spike’s Tactical midlength did not have a small gas port relative to its longer gas system, and so it functioned without any short stroking issues.

Average OEM extractor springs should be replaced beginning at 2,500 rounds and no later than 5,000. Better extractor springs will not require such frequent replacement with any ammunition – the Colt “Gold” extractor springs used in each rifle starting at 5,000 rounds were still providing reliable extraction at the 10,000 round mark, and would not have required replacement after 5,000 rounds.

Colt vs Whatever is in no way to point of the article.

Bartholomew Roberts
January 11, 2013, 07:52 PM
Colt vs Whatever is in no way to point of the article.

I didn't mean to imply it was - thus the "interesting point to me" part. However, it does show that the little differences in springs, endplates, etc. even in the cheap parts, does have a practical difference.

tahunua001
January 11, 2013, 07:56 PM
EDIT: one must wonder how WPA and herters fits in there since they are all basically the same and how the tula can be that much worse than any of the others.

Quentin2
January 12, 2013, 01:25 AM
I believe Herter's is rebadged Tula. On Cabelas site there are A LOT of complaints about stuck cases. I've experienced quite a few myself (in two ARs).

The Tula was horrible in the carbine length gas Bushmaster but they ran 6000 rounds through the Spikes midlength with much better results. However the Spikes barrel was shot out by then.

shrewd
January 13, 2013, 04:47 PM
It was a good dead but I think most general sportsman shooters will read too much into it. For practical shooting a barrel will last way past 10k rounds, closer to 30.

They were shooting constantly over a day, rapid fire. That GREATLY increased barrel erosion.

I enjoyed the wrote up but couldn't help but think that it was worthless. Yes, brass cased ammo is better. Steel is (was?) cheaper and still worth it (6 malfs in 10k rounds was it?) wow, total shocker there guys.

If anything I think the test showed that bush master sucks.
TWO poorly assembled rifles out of the box? ****ing lame.

tahunua001
January 13, 2013, 05:37 PM
shrewd, the Tula did not finish the test, it was pulled after 25 malfunctions and it didn't even make it past the 500 round mark, that is nearly 2 major malfunctions per 30rd magazine. that is atrocious by any standards.

spacecoast
January 14, 2013, 07:13 AM
Herters is definitely Tula ammo, at least in 7.62x39 (check the headstamp).

I thought it was a very thorough and fair evaluation, and the authors did a good discussion at the end. Yes, if you have to shoot the same barrel for 10K rounds with little or no cleaning, you want to be shooting brass-cased copper-jacketed ammo, but most of us will never put that many rounds downrange, and financially it may make perfect sense to shoot the cheap stuff.

I'd like to see the same comparison made with 7.62x39 to see if the lower velocity make a difference in barrel wear.

shrewd
January 14, 2013, 08:04 AM
right, but the Tula shot fine through the spikes

I do believe Tula to be a bit worse than the other steel cased stuff but that's still a rifle problem

and Herters is rebranded tula

zukiphile
January 14, 2013, 08:34 AM
Interesting test in that it shows that chrome lining is not a panacea. I would be interested to see such a test on a melanite treated barrel.

I could not read the test without imagining the Luckygunner people performing a tally of the current retail price of 30,000 rounds of 5.56.

Alabama Shooter
January 14, 2013, 11:24 AM
Interesting test in that it shows that chrome lining is not a panacea. I would be interested to see such a test on a melanite treated barrel.

Actually it functioned exactly the way it was supposed to. Army tests have recognized years ago that the mean time between failure for chrome lined barrels is 9600 rounds (shooting USGI ammo, not Russian Bi-metal stuff).