AR 57 brass prolem?

Discuss rifles chambered for the 5.7x28mm; P90, PS90, and AR57.
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VITALIY
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AR 57 brass prolem?

Post by VITALIY » 13 Dec 2008, 17:14

I'm experiencing a bid of a problem with my AR57: the brass that comes out is totally destroyed :?:
I mean totaly: the primers poping out; primer pockets are overstretched; there are heavy bolt marks on cases, and in one extream case one of the shells came out looking like .30 corbine case :?:
There is no difference on what ammo i use, factory or reloads, and actualy the reloads with crimp seam to handle it better than factory rounds. Go figure :?:
Just wonder if i'm the only one with that kind of problem.

Grantness
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Re: AR 57 brass prolem?

Post by Grantness » 13 Dec 2008, 17:26

thats scary :ponder: You havnt had any seperations yet have you?

VITALIY
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Re: AR 57 brass prolem?

Post by VITALIY » 13 Dec 2008, 17:32

No, but, the case(ss195) that came out looking like .30 corbine has bobled at the base. Guess any more pressure and it would have explouded.
I've gave it to MO for examination, maybe he can post a picture later when he is available.

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MrSlippyFist
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Re: AR 57 brass prolem?

Post by MrSlippyFist » 13 Dec 2008, 18:33

I've reloaded 2x fired brass out of the AR57 and it seems to be holding up fine. Strange you're having that instance with factory ammo. How's the accuracy with that upper?
Embrace the Suck

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jmz5
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Re: AR 57 brass prolem?

Post by jmz5 » 13 Dec 2008, 18:41

Maybe you got a lemon.
كاف

VITALIY
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Re: AR 57 brass prolem?

Post by VITALIY » 13 Dec 2008, 18:55

It's pretty accurete, 3-4" groupes at 100yard with iron sights, and i'm no expert.
One clue that i have is: it uppears to have no throat at all, i mean that the rifling lands seam to start without tapering. If i chamber the round, and then extract it, often the bullet will seat dipper with deep sharp marks from lands.

VITALIY
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Re: AR 57 brass prolem?

Post by VITALIY » 13 Dec 2008, 19:03

jmz5 wrote:Maybe you got a lemon.
I doubt that. It wos spotless when i've got it. :?:

VITALIY
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Re: AR 57 brass prolem?

Post by VITALIY » 13 Dec 2008, 20:17

Here is the sized and trimmed case after being chamberd:
Image
Image

JJH
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Re: AR 57 brass prolem?

Post by JJH » 13 Dec 2008, 20:45

I had a similar problem years ago with a Olympic Arms OA93, the chamber was improerly cut and Olympic Arms had to replace the barrel. Get in touch with the manufacturer and get them to fix it.

VITALIY
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Re: AR 57 brass prolem?

Post by VITALIY » 13 Dec 2008, 21:03

JJH wrote:I had a similar problem years ago with a Olympic Arms OA93, the chamber was improerly cut and Olympic Arms had to replace the barrel. Get in touch with the manufacturer and get them to fix it.
I guess :?:

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fatherfoof
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Re: AR 57 brass prolem?

Post by fatherfoof » 13 Dec 2008, 22:40

Obviously defect covered covered by manufacturer to avoid litigation. If you know a police firearms tool mark examiner, they can pinpoint the problem. Otherwise you'd be safe ignoring opinions of guessing well meaning posts. Too many experts who never worked with guns under a microscope in a lab and were required to be right and testify under oath in court. These are all well meaning guys, but for safety sake read this so we avoid posting a hospital address to which we have to send you get well cards.

Grantness
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Re: AR 57 brass prolem?

Post by Grantness » 13 Dec 2008, 23:28

I'd say if Slippy isnt having the same problem, then it is not specific to the AR57... Call it in, get them to replace/fix it!

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fatherfoof
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Re: AR 57 brass prolem?

Post by fatherfoof » 13 Dec 2008, 23:39

Great suggestion Grant! You know this round as well as anyone and while some things are easy fixes, this is a bit beyond a homemade rapair. Appreciate all the past posts you put up. Several contributed to why I chose to sign up here while avoiding the mass of ballistic nonsense on other forums.

VITALIY
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Re: AR 57 brass prolem?

Post by VITALIY » 14 Dec 2008, 08:34

Thank you all guys for greate responces. I know some one who is a greate gunsmith, so i'll let him look at it. I may not be the expert, but my got filling is that all it needs is a throat cut little dipper. Still love that thing, and would hate to part with it for longer than one day. I'll keep you posted.

Fatherfoof, i've being on this forum for allmost 3 years now, and find every one here well meaning, and allways heave respected their suggestchens and opinions. I,ve being allways treated with respect here, and did the same to every one in return. Is it my language barier, or wos there something offensive in my posts? If so, than i deffenetly did not mean to offend any one. And if any one feals offended buy any of my posts, please let me know.
Thank's to every one!
And forgive me if that vos just my french :)

Grantness
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Re: AR 57 brass prolem?

Post by Grantness » 14 Dec 2008, 11:26

Glad I could help fatherfoof :thumb: I wouldnt say I know the cartridge as well as ANYONE. Most of what I know, I learned here. ...And most of that came from Jay and Ryan at Elite Ammunition.

Vitaly: I dont think fatherfoof was bothered my anything YOU said (you have always been respectful AND helpful)... It was some of the people on other forums that were getting to him (at least thats what I gathered).

gotem
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Re: AR 57 brass prolem?

Post by gotem » 14 Dec 2008, 12:11

VITALIY wrote:I'm experiencing a bid of a problem with my AR57: the brass that comes out is totally destroyed :?:
I mean totaly: the primers poping out; primer pockets are overstretched; there are heavy bolt marks on cases, and in one extream case one of the shells came out looking like .30 corbine case :?:
There is no difference on what ammo i use, factory or reloads, and actualy the reloads with crimp seam to handle it better than factory rounds. Go figure :?:
Just wonder if i'm the only one with that kind of problem.
Sounds like one of the early bolts that might have come out of heat treatment incorrectly.
Just contact and send your bolt back to 57CENTER LLC at 8525 152nd NE Redmond, WA 98052. Great company ! They will send you a new one and take care of you right away. There tech # is (206)818-9006 Ron

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fatherfoof
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Re: AR 57 brass prolem?

Post by fatherfoof » 14 Dec 2008, 13:09

VITALIY, Absolutely not. I have the deepest respect for the fellows here. I merely think you have a dangerous looking situation and don't want to see anybody injured. I sincerely meant no offense to anyone. I think all would agree there are things we can work on, but sometimes for safety sake the gunsmith is a wiser choice. That is why I agree with Grant in that your issue should be resolved professionally.

VITALIY
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Re: AR 57 brass prolem?

Post by VITALIY » 14 Dec 2008, 18:12

Many thank's to every one for replyes!
Will deffenetly contact AR57 center, and let the professionals take care of it.
Will post as soon as i'll get any news.

17DoubleE
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Re: AR 57 brass prolem?

Post by 17DoubleE » 17 Dec 2008, 15:44

Hello everybody, my first post here:

My AR57 upper came with a heavy recoil buffer. Just wondering if you happened to install this heavier buffer in your AR? What you're experiencing reminds me of what issues can result in a 10/22 when converting them to shoot the 17M2 cartridge if mass isn't added to the bolt. Of couse in this case the buffer doesn't add mass to the bolt itself so maybe my hunch is way off.

I've not yet had the chance to try out my AR57 so I can't yet comment on how mine is working.

IDTANDY
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Re: AR 57 brass prolem?

Post by IDTANDY » 17 Dec 2008, 16:20

Haven't had any problems with my AR-57.Have put 400 rounds through.Did you put the heavier buffer in?

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RadCat
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Re: AR 57 brass prolem?

Post by RadCat » 02 Jan 2009, 19:07

VITALIY wrote:It's pretty accurete, 3-4" groupes at 100yard with iron sights, and i'm no expert.
One clue that i have is: it uppears to have no throat at all, i mean that the rifling lands seam to start without tapering. If i chamber the round, and then extract it, often the bullet will seat dipper with deep sharp marks from lands.
A smooth transition of bullet from chamber into rifling is extremely important in any blowback design without significant delay in its action. If anything I would recommend a throat "honing" job be done, making sure there is no 'pre"-contact with the rifling upon merely chambering. If that "jamming" is present so will be the higher initial pressures which will start shoving the case back under full pressure before the bullet leaves the case. Ideally the bullet should be out of the barrel before the chamber/breech opens. From experience and by looking at the amount the shoulder moves forward, it would indicate the proportion of balancing in the load and your components. The premature contact in your rifling specifically indicates bad "geometry". Again ... the bullet jamming the rifling in a straight blow back action is asking for cases to blow up. When you state that your shoulder is gone and the brass looks like 30 carbine brass ... well ... what can I say.

I would send back the entire assembly to the manufacturer. I don't think they would mind at all. Frankly, they would probably wish they had heard about it first, and right away. And, for sure will stand by their work, and have a cure for your problem. After you get it back, enjoy it and remember to work within its limitations in design.

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