Let's face it. Cheetos and Shasta?  You were gonna die young anyway.

Nope- still a design flaw.  They made a decision and left in sharp corners, when they could have just as easily rounded them.  They did not have as high of a safety factor as a result, which bit them in the ass when the polymer issue showed up.  That is a flaw.  Would have cost nothing to use rounded corners to begin with.  Radiusing the corners now is a half assed way of dealing with it and looks like shit from a design point of view.  They made a decision to go square corner, it concentrated the stress at the corner as a result, just a dumb move on an otherwise well thought out rifle.  It is a basic design consideration.  

Or maybe that degree I got in Mechanical Engineering (Design option) is just for show and I don’t know shit about it…

Rounded corners are better with polymer as well.

The flaw IS the polymer issue you alluded to and that's why rounded corners won't magically fix stocks breaking in other locations (see pics posted earlier). You're incorrectly attributing the problem to the design from the 1970's that's sound for 40+ years. In manufacturing basics, the problem is/was in either the Procurement of raw materials and associated checks to be sure it meets specs, or the Production of being molded or other manufacturing process, and Quality Control testing to be sure finished product meets the required standards. It's no different than if they made a batch of bad barrels out of pot metal.

Nonsense.  I'm in my prime ...

Agreed a design flaw is not the problem. They have been making these things for a long time and this is a recent problem.

This assumes that they didn't intentionally change the design at all since it was adopted in 1970.  We know the design has changed as the latest Steyr offered has different components compared to when it was launched in 1970.  Wiki tells me there was over 20 configuration changes in the Steyr production so we know the design isn't stagnant.

If they added/removed rounded the corners of the Stocks that is a physical design change that requires a drawing update.  

It is likely this change wasn't just a procurement for a new supplier or a bad batch as we know that the issue has been going on for years and wasn't fixed.  They most likely decided to try something new to be better/cheaper/less over designed/or isn't procurable for some reason

Example reasons we have seen in other areas
1.  Asbestos being discontinued for health reasons and replacement materials used even though asbestos has been used for centuries
2.  Metallurgy heat treatment moving to gas quench instead of oil due to oil being dangerous/not as uniform even though it was used for centuries
3.  Leaded gas to regular gas because Lead
4.  Ethanol added to gas for emissions

They did some kind of engineering assessment, that was flawed, showing the new material design would work and pushed it into production.  Once in production it showed their analysis was flawed and now they are trying to find a solution.  Obviously they ruled out the solution of going back to the original material/production method for some reason.

So what you are saying is it wasn't a design flaw.

I am saying it could be a design flaw.

If they made a change to their drawings, like they would have had to for the rounded corners, and it failed when their Engineering said it would work, that is a design flaw.

If they made a change to the material, and decided to make it work with different corners,and it didn't work that is a design flaw.

I am saying that since the stock issue occurred for over 3+ years, presumably over multiple batches of stocks, it is more likely to be a design flaw than just a bad batch.

I doubt there was a design change but there could of been a process change.

- Different raw ingredient supplier
- Change to recycled material
- Change in the form release agent
- Change in the forming temperature
- Change in the post production handling / assembly
- Untested change in the colorant used (we all know that black polymer is the most stable)
- Decreased QA / QC

If you want to call these "design changes" then so be it, but a production issue resulting from a process or material change is likely a more robust explanation.

We know the corners are a design change.

If the material of the stock (including the recycled material) changed, that is a design change.
Changing of the colorant is a design change.  (Color in Polymers does have structural impacts especially when dealing with sunlight).  
If they changed the manufacturing process steps by changing temp or form release, that is also a design change.  It would be called out in the stock drawing as Assemble with Process ABC1 to Process ABC2.

If they didn't document the process well at one supplier (and that supplier did extra steps) and they took production to a different supplier who followed the same steps but didn't do the extra undocumented ones that is also a design defect and would require a drawing change.


We don't know if they changed just the supplier, the tooling, or the material.  Because Steyr still hasn't publicly acknowledged their screw up or provided their root cause and corrective course of action.  Replacing damaged stocks under warranty is not a Corrective Action to keep it from happening again.

From the perspective of an Engineer, the Process used to make something is part of the design and needs to be controlled by Engineering so it is repeatable.

If they had a process to make thing X and the person building the thing didn't follow the process that is QA.  If it is tested and fails QA testing (or passes QA testing and makes it to customers) It could be that it was assembled badly OR that the design wasn't good enough to account for all conditions.  If QA catches it before it goes to the customer the thing gets reworked or scrapped it goes into "production yield", which isn't necessary a defect but increases price to the customer.  If QA doesn't catch it, but should have that is a QA escape.  If QA didn't test the issue before it went to the customer, that is an Engineering problem but not necessary a design defect (Because yield).

Nope- it was foolish to make square corners from day one.  Why build in a stress concentration when you don’t need to?  

Design isn’t always about today, it is also anticipating what might happen in the future.  Like plastic aging, or getting in a batch of polymer that isn’t 100% up to spec?   It is also saying I want it as stout as possible, not just “good enough”.  Especially when there is no cost or difficulty to do so.

If I can make something that will last 100k rounds with square corners, or make it last 200k rounds by rounding the corners (which costs literally zero to do), which is the better design?


And Steyr has no excuse on making that decision, knowing the changes they made to their STG-58 FAL receiver:

Type 1 (early Steyr STG-58 receiver)- weighed slightly less, had the most lightening cuts to remove the most weight.  Found to crack under heavy usage.  

Type 2 (late Steyr STG-58 receiver) weighed slightly more as they did less lightening cuts.  They rounded some corners as well where they added back steel.  In testing these lasted a hell of a lot longer than a Type 1.

FN Type 3- cost saving measure by FN (not used by Steyr)- Cast receiver instead of the original forging.  No lightening cuts, weighed a lot more than a Type 1 or 2.  

So it isn’t like Steyr never heard of stress concentrations before….


Basically- why design in a potential failure point, when you can make it stronger from day 1 for no extra cost?  Radiusing a corner isn’t exactly unusual.  


If Steyr had rounded the corners from day 1, and added a raised boss reinforcement around the holes, I bet we would not have seen 95% of these failures.  (Some have failed at random locations, so we would have seen those).

Also the new “rounded corners” are not real rounded corners.  They are rounding out the square corners by removing even more material.  They still haven’t actually changed from a square corner design at the mold stage.  

I would consider the first version polymer CAR-15 stock to have a similar design flaw- they went from an aluminum stock to polymer, but made it a bit thin on the baseplate, lacked gusseting or reinforcing in the transition to the baseplate, and had a fairly squared off corner instead.  Those stocks are great- iconic, retro, etc.  They also break all the damned time in real life usage.  The later updated version for the M4 seriously fixed those issues.  It was still a design flaw, even though it was used for many years successfully….there was just a better way it could have been designed from the beginning.

Got mine in October, the corners look radiused to me..

Attached File

Do we know what is causing the cracks? I mean from what activity...? They crack just from shooting the rifle or are ya'll doing combat equipment jumps with them?

I hope to pick up mine tomorrow. A new, black stocked M1 A3.

A properly radiused corner would be a simple rectangular hole with rounded corners.  That is not what you see in that photo at all.  What you are seeing is the bandaid radiusing job.  

Steyr is simply taking a file or dremel tool with a rotary bit to the sharp squared corners to round them out.  That is a way to stop cracks from spreading or starting in a material.  It is not how anyone would design it on purpose from the beginning, because you end up removing extra material, having holes that are neither square nor rectangular with radiused corners, and it looks like they are doing it by hand (uneven radiusing) so it is adding labor.  Literally a bandaid mitigation, not a proper design fix.  

But it does work, even if it looks like shit.  I took a round file to mine and made it match my other one, which came with 4 corners clearly done by hand….

With Steyr’s 40 years and thousands of stocks without issues, your comments are what seems foolish.



Not sure if you even hear yourself?!? Specific material specs are inherent to design. If the materials don’t meet the spec, it’s a materials issue. Like I said before, it's no different than if they made a batch of bad barrels out of pot metal. Calling it a design flaw makes zero sense. That said, at this point, I don’t care what anyone calls it. Carry on.

I'm about to pick up my first AUG (monday?) so I'm ignorant about them. But if the squared, non-radiused holes held up fine for 40 years, there must be something else at play. Although we probably all agree that radiused holes, rounded corners are less of a stress point .vs sharp corners. But since Steyr has started to radius the holes, they are attempting to remedy a problem. But maybe the wrong problem since square holes were not a problem for 40 years.

Things in manufacturing processes change. Sometimes (typically) for financial reasons as cutting a corner that saves a penny and is "just as good" has caused lots of problems. Sometimes it's legislative pressure as certain procedures become banned for idiotic environmental priorities (like the OEM tennefer on Glocks seems to have been superior but got banned by the greenies). Supply pressures, like happened during covid, may also play a role. Since Steyr is radiusing holes, I'm betting the newer plastic is NOT "just as good" as the old. We'll find out 10 years from now that some asshole mandated biodegradable plastic or some such shit for climate change

It would be interesting to see the inside of those cracked stocks…
What if the cracking is not starting from the outer sharp corners, but rather from an inner part of the stock? I’m thinking about an incomplete injection mold..

Btw,
Is steyr filing all newer stocks?
If not the filing may just be a deburring process…
Why should they file some and leave others with sharp corners if it’s a “known design flaw”?
How would they know which stocks need to be filed?

Another one.

Few week old replacement stock cracking 150rds later.

https://www.reddit.com/r/AUG/s/8qzLjhRKzT

And that one appears to have the rounded corners.

I picked up my new, never fired, black AUG M1 A3. It appears to have radiused corners as in the picture a few posts up. Also appears to have a 1/3" crack or scratch running from one corner towards the ejection port. I will try to take it apart later to confirm if its a crack or scratch. Looks like a crack under magnifier...

edit: I "think" it's just a scratch but I was unable to remove the metal disassembly bolt (dont know what it's called but it's the square thing from the picture above regarding the radiused corners) so I couldn't look behind it from the inside. I'd post some pics if I had an actual account but I doubt anyone could see better in a potato pic than me with a magnifier. I will monitor it and if the "scratch" grows, I will panic again.

p.s. If magpul comes out with AUG stocks, I'll probably be a buy.

Is Magpul saying they’re developing AUG stock or something?

No, I think he means that if Magpul did start offering reliable stock assemblies for them, he'd be a buyer.

All of this cracking is pretty terrible, and makes me glad I have old stocks.

It’s honestly the one thing that’s keeping me from buying a colored AUG stock. It doesn’t seem to be happening to the black stocks though which is interesting.

So nobody has reported a black one that cracked?
That is interesting.

I mean, I could’ve missed it but, so far as I’ve seen, it’s not black stocks. Correct me if I’m wrong because if that’s the case, and the black ones are cracking, too, then the AUG is off my list for sometime to come.

Honestly, if or, when Steyr gets the AUG issue figured out, they need to make a very public statement, apologizing for the previous problems, and that the formula has been changed or something else and this problem won’t happen again.  They’re literally ruining the AUGs reputation here in the United States.

No. I'm just dreaming. But IF they came out with a replacement for maybe $200-$300...I'd probably try one.

Probably me. I just posted about my brand new not-yet-fired black AUG. I saw something that looks like a crack coming off a corner from the take-down bolt. But I think it's a scratch (I hope) but I haven't found a way to remove the take-down bolt to look inside to see if there is indeed a crack. Maybe someone got clumsy installing the bolt or radiusing the corners and put a scratch on the plastic. If it grows, then I will know...

Here's hoping it's just a scratch then.


Please let us know later.

FBT made some super cool carbon fiber stocks for the AUG:

https://www.thefirearmblog.com/blog/2019/09/16/adihex-2019-fine-ballistic-tools-fbt-from-austria/

https://www.reddit.com/r/GunPorn/comments/1142hpf/i_prefer_easy_puzzles_steyr_aug_z_a3_with_fbt/

https://www.reddit.com/r/AUG/comments/tnltw3/has_anyone_got_one_of_these_fbt_carbon_fibre/



This is likely "too much of a good thing" / way more $$ then most of us could afford.

But there are now Industrial size Carbon Fiber 3D printers, capable of producing parts that are quite strong - possibly much stronger then the factory stock.



If someone could work up a CAD / STL etc of the AUG stock, then they could be printed in CF. These would both be less likely to crack and ensure that no matter what happens to Steyr / import laws, we could all get replacement stocks.

It also opens up interesting possibilities for enhanced stocks:
-integral flared magwell
-Integral shell deflector
-Grip storage(?)

We're now in the post covid era. Have they fixed the polymer issue?

At times I lurk on Reddit r/aug and I’m actually quite amazed at the number of cracked stock posts that are constantly being posted.

At first I was willing to overlook it but we are multiple years into an ongoing problem now. This stock issue is concerning to the point I don’t honestly know that I can recommend the AUG to new buyers until the stock cracking problem is fixed.

Yeah same here.

I'll always recommend an old A3 though (with its original production stock lol)

It's kinda crazy that you had to buy an AUG before a certain year to get a "known good" stock (and a nice chrome-lined barrel, if you want that) and also the optional 1:7 twist (which I guess most people don't care about).

Steyr really should address this publicly.

It seems like their USA AUG reputation is worth less to them than whatever it'd cost to fix the problem.

What’s the oldest reported cracked stock?

I remember using Archive or Google tools or something last year, couldn't find a case before ~2020 as I recall.

As in it just wasn't something that was discussed ever in relation to the AUG prior to then.

Someone has to have a STL for the Aug  stock.

We can print them by the boatload. I would even buy a larger printer just to print CF stocks.

It's the reason I just bought a Hellion instead of another AUG.

Most AUG stock breaks happen early during shooting.

If you have over 300 rds through your AUG, you are likely fine and have a good AUG.

I hate to admit it though, but this issue has been making me worried about my choice of the AUG. I'm hoping mine wasn't affected by the batch of bad polymer, but I wish there was some way to verify it other than obtaining a high round count.

A lot of the images I see online of AUG stock cracks include a suppressed AUG.  Example:



I wonder if the "back pressure" resulting from can use is over stressing the take-down latch area.

It's going to increase stress there because the extra gas from the suppressor increases bolt carrier velocity, and that's what impacts those 2 buffers in the back of the stock.

I've run a bunch of rounds through my AUG A3 with an M4-2000 (which has high back pressure) and it's suffered no ill effects. This was before the suppressor-friendly gas plug was released too. (My stock's hole for the latch is completely rectangular of course.)

I didn't use a suppressor. I just shot several hundred rounds of M855 through it on the adverse setting. Lots of recoil, but I wanted to test it to see if it would break. It lasted.

A couple questions regarding stock color, since it's been mentioned a few times.

What would the pure, raw material color be without any dyes added?  White?  If so, wouldn't white be the strongest of all colors?

If black is the natural raw polymer color, I don't see how you could dilute it enough to create Mud color, much less white.  I imagine the raw color would be similar to milk jug plastic, and dyes are added for dark colors, and some opaque white colorant is added for white stocks.  

Does anyone know how it's done, even generally with other polymers?

I dont believe the color has anything to do with it. Opaque .vs transparent plastic maybe but I doubt the color of the dye could be the main issue. We would be seeing the effects of this in numerous other products since everything is made of colored plastics now. Unless somehow the specific color dye has some harmful additives. Most likely the problem is the type of plastic itself. Too hard/brittle for repeated impacts. Or the molds have changed and there is less material at a key stress point. Changing/updating molds can be very costly. I read somewhere they are like $100K...so it may be cheaper to replace 1-3% that crack .vs new molds.

*I know jack s*it about plastics

Found a guy with cracked BLACK stock on the AUG Forum on Facebook.

Found another guy with a gun with almost 8k round before it cracked.  It WAS a newer gun ( from 2010/2022 ) but he shoots a lot.  Still.....

I started a thread about Color, Year of Mfg (or series number, such as 11USA, etc.)  and Round Count.  Let's see if I can dig anything up.

IIRC, and some of this is no-doubt made-up, but historically black plastic is considered the strongest form.  The reasons I've seen for that are that:
A) It's made black by materials that provide strengthening effects.  
B) Black is strongest opacity, giving the lowest degree of UV, etc penetration, and so the highest resistance to penetrating light damage.

Donno if this was ever true, or was only true in 1995, or whatever, but those are the reasons I've seen.  

Not really.
Yes Molds are expensive but go through a manteinace schedule regularly.. there’re moving parts that break etc.
Some parts even see wear due to the polymer flow that can slowly erode some areas.

A non functional mold is useless. Sometimes its more convenient to replace a mold rather than keep fixing it.

It’s funny you mention that because sometimes I feel like the only use mine gets is hanging in a nice frame and talking about stress concentrations. I think the bigger problem is that they changed the material and they don’t just crack in that place. As far as the corners I have a theory. Hack job, mold, repair. I’m in molding right now. And I’m seeing a lot of repairs on the fly they do not look like the original tool design.

I second that. All the fractures I’m seeing on our nylon cable carrier originate at sharp corners.