Curious just what was different about Magazine 1, I pulled apart and looked at three of them.  In particular:

Magazine #1: Green floorplate and follower
Magazine #2: Black floorplate and follower
Magazine #4: Green floorplate and follower.

The short answer - not a lot of difference that I could tell.  I will document what differences I did see, but it's minutia and I can't imagine responsible.

Here's a side-by-side of #1 and #4 - both green floorplate mags:

Left mag is #1, right mag is #2 in all photos.




The markings are completely identical.  Neither has boxes around the numbers (meaning they aren't US made mags).  Both are marked with the Steyr part number for a 30 round magazine body, on the right side:
12.00.05.0001.  Where it gets interesting is the P and the 90-over-7 markings, are on opposite sides between #1 and #4.  Odd, I have no idea why.  But Magazine #2 (black follower) has them on the same side as on #1, and #2 worked fine.  By the way, I don't know what the 90/7 means.  My best guess would be July of 1990 fabrication date, but that doesn't sound right - that's a 28 years ago.  It might be some kind of mold indicator.  Also, my 42 round mags have what appears to be the more common date markings, which I wish I could read.  They have a 3 6 9 12 circle on them, and a mark over the 12, indicating December of year #... G I'm guessing?  whatever that means - but anyway, I digress.  And the 30's don't have that wheel on them.

Back on topic - I pull out the floor plates and followers, which also are identical.  I then look inside the mag, with nothing obviously amiss...





While I don't think this is it, if you look real close, there's a rib inside the mag bodies, that's the ridge for keep round shoulders in place.  Which does seem important.  What's interesting is the side of the mag body that has the 90/7 is ever slightly rounded at the top if you look real close, and the side that has the circle P, is every so slight "peaked", vs perfectly rounded.  Is this enough to cause a difference - I really doubt it, but it is worth noting.  It's interesting that whatever mold body is used for either side, that carries over to the internal shoulder rail shape as well, and the two #1 and #4 are basically mirror images of each other.  And this carries over to Mag #2, which is the same image as #1 (and remember #2 works fine).

I looked at spring length, and all magazine springs appear to be almost identical length to me.  I do notice that Magazine #1 follower seems to go in... easier.  #4 seems to drag a little more.  But when I test with calipers, man, there's not much difference.

So - that's all I've got.  There's nothing in my inspection of #1 to really indicate why it round-jumped, yet #2 and #4 don't jump.  It could be coincidental, but in the last 7 days, Magazine #1 has had a double feed, two instances of the round almost escaping upon insertion, and one instance of a round jump entirely, upon insertion.  And none of the other mags have.

So, if anyone wants a great deal on a mag - my bestsest-so-good-it's-labeled-my-#1, is for SALE!  

Ah @JonathanwFL, curious about my "date" stamps, I went back and double looked at your photos.  Turns out, I guess mine really WERE made in July 1990, because your 30's have the more common date wheel on them where my 90/7 is, and all yours apparently were made in 2016.

Annnnnd - I'm afraid I may have some bad news.

Here's what mine look like when loaded.  See the engagement of the lips to the casing, that goes basically the whole length?  Except one of them, see how there's just a tiny gap in the forward 1/4th that one?  Turns out, that one is Magazine #1.

AUG magazine #5 - looks good; shoots good.


AUG magazine #3 - looks good. shoots good.


Aug Magazine #1 - looks.. hmm I think OK, but is the front of that body engaged?  This mag double-feed on me...


Aug Magazine #1 zoomed - well look at that, only 80% of the magazine lip is engaging the casing body, I wonder if that's important....


now let's look at your 2016 ones....  


See what I'm seeing?

That’s very interesting observation, I’ll double check my magazines. The one in the picture you linked of mine are the 40 rounders and I don’t believe I had a jam with them however I’ll double check if my 30 rounders have this issue. Although I’m not sure if that gap would cause a double feed, do you have a theory of what could happen?

Thank you for the time spent reviewing everything

"90-over-7" is actually "L/06", being a date code of May 1994. There's hundreds of thousands of those mags with the exact same date code...

That's an odd deal, but if they're saying that slow bolts can cause a double feed, have you checked the gas rings on the piston for alignment? I can tell on my AR-10 uppers exactly when the gas-rings all line up (or even two with the last one working its way there). Shit starts to go south fast. First the rounds impact low and then the gun stops cycling. The rule of thirds applies. Keep your gas rings clocked at 1/3s. Unlike my AR-10s,  the gaps in my AUG gas rings do not try to migrate toward each other.

Anybody ever intentionally alligned all 3 gas rings to create a blowby to see if the rifle still functions?

So that conversation looks like that's a screenshot of PMs with Steyr? Did you let them know you were posting screen grabs here?

Best guess I got is a slow bolt allows enough time for a round to raise high enough for the rim to engage the bolt lugs still coming back.   I guess - if that claim is true at all.

As to posting their replys- all communications of that nature should be assumed to be published on the front page of the newspaper, there is no obligation to inform them such is being posted - this isn't a private surreptitiously  recorded conversation.

So the OP sent a message to Steyr, and it sounds like they had an idea to fix rather than downtime without gun during shipping,  but he posted screen shots here for us all to discusss, because he wasn't really satisfied with their response? This discussion happened what, yesterday? did he try their fix? OTOH if any ya'll post my PMs in public, we got huge problems.

Let me roll that last post back. the OP might have gotten permission to post screen grabs.

Only the OP knows that answer. OP?

And yes lazy, I see what you;re seeing in those last couple pics. Annealing is sporadic at best. Wouldnt an engineer would notice that?

Given the message are from their Company profile answering product related questions and not a personal account with personal information. I don’t think I am obligated by law or ethical standards to ask for permission to post their responses about their publicly available products having malfunctions. What they say to me would be exactly what they would tell other customers. The information provided may help other owners get answers regarding this issue with new rifles.

What they say to customers is public information in my opinion, they are representing their company regardless of what form of messaging. If they requested I take it down, I will.

Lastly I didn’t post their response in spite or frustration? I posted so members here could see what they suggested I do and others that had similar problems so they could see to. I praised them several times for good customer service so I highly recommend you should reread what I posted before saying or suggesting that my posts were negative toward their company

Yeah, that sounds legit, but im pretty curious as to why you posted here when they seem to have been answering your questions. Were you worried that Steyr wouldnt fix an actual problem?

Oh and yo, did you check the timing on the gas rings?

I posted here first looking if others had experienced the same problem after responding to Lazies thread. After asking about their warranty they answered with the posts above. I’m sure they would take my rifle if I persisted but I was unsure if 1000 rounds of ammunition was the break in period for any modern rifle, just seemed excessive in my opinion however I am currently doing what they suggested

I’ll post pictures of the gas rings soon

standing by for pix.

Two are almost aligned. 2, 6 and 10 oclock.

But damn, that's the cleanest piston after a thousand rounds that I have ever seen. For Realz. No Realzies.

can you elaborate on your theory? I’m not sure I understand

I do appreciate the help, I’ll separate them like you said to see if that helps

did you scrub the shit out of your piston lately? I think I saw you said you had 1K rounds through that gun. Your piston and spring tell a different story. No chance there's been more than a couple boxes of amo past that.

I clean and maintain my rifle every time I use it, I don’t let it build up. I’ve done likely way over 1000 rounds But I’m not sure on the exact number. I’ve been to the range around 10 times and shoot at a minimum of a 100 rounds, if not more

Here’s at least 4 separate range trips of letting a number of people use the rifle and ammunition used was 100-300 per trip







And yes they gave me permission to post these photos of them

NRAar has a good point. Your gun is really really clean. If I had a brand new AUG I wouldn't clean it until it malfunctioned due to the gunk. AUG's have a design such that cleaning should be minimal of effort and frequency. I once pulled the piston out of my A1 MG host and had to chisel off the accumulated and burnt on carbon on the piston face.

Then there's the photo evidence of Walmart .223 bulk pack. It's notoriously underpowered.

Let's put it all together now. You have an STG77 with the 20" barrel, use underpowered .223 ammo, and clean the AUG religiously after what you say is maybe 100rds at minimum each outing.

The STG77's are about a year and a half old, having an STG77 myself the springs are typical new AUG - stiff and heavy. The AUG 20" barrels have a different recoil implulse than the 16" AUG's, I can't quantify it, but it is softer. Underpowered ammo is going to cause issues with a new AUG. Cleaning the AUG too much doesn't allow carbon to help seal off your gas system.

Assuming weak ammo is creating less pressure in your gas system, with an added drop of pressure from a 20" barrel and perhaps leaking piston because it's not been packed off with carbon, adding to that heavy as hell springs in the carrier rods and in the hammer pack, it could all be a perfect recipe for the malfunction you're experiencing. Now let's assume you have a funky magazine or two. You're SOL.

There's lots of great advice in this thread, many experienced user's and Steyr's rep's advice is solid. All of it being free, take it for what it is. Good luck in your course. If you still have problems, Herbert is a good guy but you'll be out your gun during the wait.

I got to say, Jonathan, I'm guilty of the very same behavior. Being a non mil guy I probably tend to overclean my weapons so I'll quit that. And I'll assemble my A3 and continue to test with my crappy mag, although a cursory search of my stash didn't reveal any more of them so maybe it came with a rifle, maybe my A3M1?

I read before that 16" and 20" have the same size gas port, I had to search again to find it

AUG gas port sizes, click here

I thought it sounded questionable, possibly a typo......but if that is true, the 20" would have considerably more port pressure than a 16" barreled AUG.

Thank you for the advice, I didn’t realize carbon build up is a good thing, I’ll hold off cleaning until it’s throughly shoot

Steyr will absolutely come through for you if it comes down to having send a rifle in.

I’ve been nothing but impressed when I had to use them.

On lunch break during the class, had bolt back all week, rifle on adverse settings using a mix of federal and AE

Only had one double feed in the first couple mags,

So far everything else has been fine but will shoot more after lunch

That poor rifle.  Let's think logically.

*AUGs are generally considered somewhat overgassed, even on normal setting with a 16" barrel, not a 20".  A 20 supposedly has the same size gas port, so should flow even more gas into the cylinder.

*Adverse setting is for adverse conditions, such as being filthy or full of dirt, soot, or cold dried out lube, etc.  OP's rifle has fired well over 1000 rounds, and is kept oiled and meticulously clean.  Why, again should this well broken in, clean and oiled rifle require adverse setting?  Why run it there for hundreds of rounds?  What exactly is that going to do?  Everything in the AUG that can cause friction is plastic on plastic or highly polished chrome and steel except the springs, right?  Doesn't normal setting shoving the bolt all the way back "break in" the spring enough?  Do you think battering the parts back faster into the stock helps break it in? Even after 1500 rounds?

*Everyone else's AUG works fine pretty much out of the box on normal setting.

Now I'm reading in this thread that guns don't work properly as designed unless they have a build up of carbon.  (?)

Not that it matters what I believe, but BTW I'm one that thinks repeated motion is most likely what weakens a spring over time, not sitting in one position, and the "leave the bolt locked back for a month" thing isn't all that.  I read somewhere where actual WW2 1911 magazines were found fully loaded since the '40s and when tested, had the full new specification stiffness.  Of course anyone can type anything online, who knows.

So, at first I thought the rifle was maybe overgassed.  I still don't think it's the mags.  I don't know what's wrong, and in my opinion, nobody is going to pin it down via this thread.  I would absolutely send it back to Steyr, or else accept that a double feed every 300 rounds is how it's going to be.

I just feel bad thinking of OP abusing his gun on high setting because folks suggested it to soften up the springs.

Gut instinct tells me none of this is right.

3 double feeds out of 500 rounds, different magazines, all adverse setting

It’s not really ideal for $2000 gun m

Send it back. You're right, a $2000 rifle should be flawless. How many KAC SR15s go back for repair? Not very many, there seems to be a high amount of AUGs being returned to Steyr for a myriad of issues, including mine. Steyr needs to step up their quality control.

Yeah I just told the guy, pretty much the advice didn’t work and I’d like to send it for repair or just inspection

I got a bit of a laugh out of that when I saw Maleante post it. Seems rather illogical on the face of it in my opinion.

He told me to call and organize sending it back, hopefully that fixes things

I never said that an AUG will not work properly without carbon built up and if someone took my intent to help the OP with his specific problem to mean such, then they missed the point of what was written.

FWIW, the gentleman at Steyr who helped the OP throughout his ordeal over this last week and I have spoken at length regarding the issues presented by his gun since OP made it public. Everything offered to OP in this thread is solid advice for diagnosis of his problem (maybe except my point on bbl pressure that mad madrigan brought up) without having the gun in hand AND it was offered as an alternative to sending the gun into Steyr.

In the end it doesn't matter. The gun is going back to Steyr where their gunsmith will diagnose and fix the problem.

Steyr received my rifle on Friday and fixed the rifle by Monday now that is some fast service. Steyr has some of the best customer service! I will receive the rifle tomorrow. I believe they replaced the bolt and/or extractor. I believe Herbert stated they received the same malfunction when testing and the new parts solved it. He could have done more but I didn’t ask, as long as the rifle works I am happy.

+1 for Steyr

Gun arrived this week, will test first when I get chance