Not to Hijack Lazy’s thread I decided to make a new one.

I have an STG 77, it’s an awesome rife however I occasionally get double feeds every other range trips while using different ammo, and magazines. This has occurred on both gas settings. Some trips it will run 100% and others it will have hiccups. I do a full detail clean after every range trip and there is no noticeable broken parts.

During the break in period It was common however after that was complete  it ran well and no issue. Fast forward a couple hundred rounds It started occurring several times after using Winchester white box ammo which jammed the gun almost every Magazine. I used the remaining white box ammo  this weekend in a full Auto AR15 and worked 100% so I’m not sure it’s the ammo.
It recently occurred 2 weeks ago one time shooting with my dad, with federal ammo but 100% this weekend.

Im taking it to a class this weekend so hopefully it runs without jamming on me
It’s concerning as this is my primary home defense rifle and for a $2000 rifle, it shouldn’t be extremely finicky to work correctly.

Lazy suggested it’s caused by bullets bouncing out of the magazine while firing, does anyone else experience this?

Here’s the examples









UPDATE: will be sending it back to Steyr for repair, after 1500 round malfunctions are still consistently occurring every 200 rounds. Will update when I get the rifle back. This is my only firearm at the moment so hopefully their turn around time is fast

Both rounds are always live? USUALLY mag related.

I have 4 Augs and never had any issues even close to that? I am guessing It is mag related also as the Aug Platforms ar usually super solid. Mark mags and see if a certain mag is to blame and keep us posted if it is the gun I would contact steyr and they will make it right.

Rounds popping out of mag causing double feed.

"But muh AUG mags so reliabuh!"

Do you have any Magpul AUG magazines to use as a comparison? They seem to retain the top round a little better.
Did you buy all your magazines at the same time? Maybe that day they were off at the factory.

Steyr has been easy to deal with my AUG.

Sorry to hear about your frustration with the platform. Someone who knows better than me could chime in.

Touche'   (F' you, but Touch'e ; I LOL'd )

So this is very not-OK.  As others note, top suspect is the mag.  So when you get a chance, please post detailed photos of the mags being used.  If it's multiple mags doing it - are they actually different mags, or are they maybe from the same lot.  I want to see the follower, the lips, the front of the mag, the indicator markings.  Who did you buy them from?  All of mine are from .44 Mag.com and out of 4600 rounds, I've had this happen only once - but I'm watching it!

More details will help.  When the jam occurs, where in the mag cycle is it?  Full (ish) mag with full spring tension?  Near the end of the mag cycle (weak spring tension), etc?

Pull apart your mag and clean it.  Also, take some photos showing just exactly how you're putting the spring back in (orientation).

AUG stocks have a cut in the bottom through which the mag passes.  There is a rim in there that is probably by-design very close to the outside dimensions of a mag - and I suspect that helps keep the mag from swelling, and keeps it aligned.  Take a close look at that rim, and see if it's sloppy (probably not that well explained).

Also, load up a couple of the mags, and post photos from several angles of what one of your mags looks like while it's loaded.  Is the nose of the 2nd round trying to sneak up and out?  Try pushing forward the first round, how is the second round behaving.

Unload your AUG, drop the bolt, flip it over.  Look down the mag-well.  See the bottom of the bolt carrier - is it smooth?  How about the end of it, any burrs, or anything that might snag the rim of the top round while it's flying BACK in the cycle?  How about the bolt, any burrs or anything funny on those bottom lugs that might also be contacting the rim of the top round on it's way back?

Gas setting - it's on Normal of course?  Take a photo of what that port hole looks like.

Frankly I think AUG's are over-gassed.  I don't suppose you have a bore-camera that can give an idea how if your gas port is oversized?

Try a few shots with gas in Grenade Launcher mode (gas turned off), and manually cycle.  Cycle it weak, cycle it hard.  Everything OK?

The trigger group locking pin.  Are you sure it's installed right?  Which is to say, you insert the trigger group (with gun held level so the bolt-lock is hanging correctly and works right), insert the rubber butt plate, push in the center of the butt plate to allow clearance of the pin and push the pin all the way through.  Let everything go, then tug on the pin for 1/16" for it to snap into set.  That's being done right?  Post a photo on both sides of the pin, showing how much is sticking out.

Bolt-carrier group - what does it hit at the end of its stroke?  How does that impact zone look?  Also, do you have the little roller doo-dad on top of your bolt carrier still?

Detailed cleaning every range outing: So stop.  If it's super clean and well lubbed, bolt carrier velocity is going to be maximal, on a gun that's already over-gassed.  Let it get dirty, let the rings coke up.  Keep it lightly (lightly) lubed; an AUG can go a long time between cleaning.  Maybe this has nothing to do with it, but something to try.

All that said, my top suspect is still the mags - so be sure to post those detailed mag photos first chance you get sir.

if it ends up not being your mag call Steyr, they will make it right.

I’ll post detailed photos tonight, on Sunday I’m going to Florida Firearm Training Advanced Rifle class. It requires 500 rounds, I’ll take note if any of the magazines has issues and mark them for further inspection. I have a spare parts kit so I can replace any minor parts of required

Do your mags have a clear square around the round count numbers?

My NATO aug had bad double feeds but it was new.
Haven't tried it since

40 rounder markings


30 rounder markings



Magazine that came with the rifle



Inside look at the rifle

Thanks!  Great series of photos.

First off, I never really noticed it before, but apparently in AUG mags, the nose of not just the first round, but also the second round - can clear.  That's ... interesting.  I took some photos of my mags, to confirm, and they look pretty much the same as yours - I see nothing obviously amiss with your mags, or any indicator you got a different lesser-fabricator's mags.





To be honest, I'm less certain now that it's a round-jumping out, than I was before.  It never occurred to me it would be possible for the second round to clear the front of mag, but clearly it can.  I'm almost starting to wonder if there's something about your stock that is allowing the mag to be inserted a touch too high, or isn't securing it so that it can wobble (cant) forward during recoil - just enough to somehow expose the second round's bottom to the bottom of the bolt, now.

I'm beginning to wonder if this is a stock issue, more than a mag issue.

Here's a few photos showing how mine sits in and engages.  These are not easy pictures to take and what we want to see, isn't easy to see - but it's what I could get for you.





I'm going to go grab mine again, and try to get a feel on how much canting play my mags can do, such as under recoil - be right back....

Interesting.  Ok, so here's what it looks like during initial engagement in normal cycling.



But if you try to cam the magazine forward - the AUG magazine is bottomed out and pressed forward by the mag release button and that spring.  Upon recoil, the gun will try to move back, and the mag will try not to.  Under that physics, the mag is locked in pretty good, and can't move any further - so by my reckoning, this should be fine.  Here's the dimensions I got with some Calipers (this is highly dependant on where you touch the calipers of course)


BUT  If, however for some odd reason, the bottom of the magazine tries to move back, and gun stays put, it can wiggle by compressing the mag-release spring.  And in so doing, move the ass of the second round up.  Will this cause a double feed?  Turns out, it does.  When I tested it, you can see in the below photo, how the second round is trying to go forward now too - and it's nose is pressed against the front of the mag now.  In this photo, I actually took my hand off the charging handle, and the gun is actually locked up, by the rim of the second shell against the front of the mag.  A light whack (Such as recoil), and those two rounds are going to try and feed at the same time.

So based on my investigations and tests, I'm wondering if your issue is a stock issue, not a mag issue.  It might just need a stronger mag-release spring, or the dimensions/cut on the inside of the stock might be off.  Not sure.

I tried to replicate the double feed theory that you mentioned and couldn’t get the bolt to come close to pick up the second round or popping one of the rounds in the Magazine while inserted, I’ll try it will all magazines tonight

Do the double feeds happen on the 1st rounds, middle of the mag, end of the mag?

First off - apparently it's time to clean my gun; these blown up photos make mine look filthy!

I need to go check again tonight - because you're right, it does seem unlikely that the second round was raised far enough from cam'ing the mag, to engage the bolt.  That's a long way to raise that second round up.   Yet, somehow, it did try to double-feed when I pulled and held the mag back.   It might just be the angle is causing the casings to drag against each enough enough that the 2nd one wants to carry forward with the first one.   I'm going to try again tonight and look further into the behavior.

Haha, cheap shot, I know but this definitely isn't the first time I have seen this issue with AUGs. Not saying it is super common, but it does happen.

When I point that out here the pitchforks always come out but it is what it is.

I've seen this happen with AR-15s too but only with shitty Orlite mags.

The rounds only pop out during the firing cycle, probably when the bolt carrier hits the rear of its travel.

It isn't going to happen when you are cycling it by hand, that's a waste of time.

Set up a camera on a tripod looking into the ejection port with good lighting and film it while you shoot. You will see what I am talking about if you have a camera that shoots 60 frames per second or more.

I bought the Corvus Enhanced Magazine release, hopefully that better holds the magazine and prevents the round popping

How long is shipping from Corvus?

OK, I am drawn in.  From the beginning of this thread, my money was on gas.  I may be dead wrong, but I bet there's nothing wrong with those mags.

Different ammo, different magazines, same problem. The constant is the gun itself, and it has always done this.  Has anyone ever heard of another AUG doing this?

Both of the rounds may be spit out, not pushed out.  The top round in the double feed is resting pretty high on the bolt.

Lazy asked about the gas settings.  Is it on normal?

1st vote:  Gas
2nd vote:  Out of spec stock

Gas is correct setting and has occurred on both settings, I have a extra Suppressor gas port I could try but I don’t think it’s the gas. This jam is rare with most ammo but most common with the Winchester Ammo. If I have issues this weekend shooting 500 rounds in a class, I’ll contact Steyr for a replacement

Hhmm....

The stock assembly is welded together down the center during manufacturing, IIRC.

Perhaps the stock is out of tolerance just enough to allow the magazine to misfeed.

Quit burning up ammo and send it in to Steyr, let them fix their mistakes.

This is what Steyr has to say regarding the issue. I’ll follow what they recommend but 1000 rounds to break in a rifle seems excessive but they are the experts

Jonathan, read the bottom of Lazy's thread, page four.

Tomorrow, unless it snows, I'm going to the range with ~60 rounds of green tip ammo and a domestically made AUG mag, an Austrian AUG mag and a magpul mag so I can reenact mcantu's idea about mags and ammo causing this issue.

I spoke with a buddy tonight who had this same double feed with green tip ammo in my rifle. The unknown is what mags were used.
I'll post in lazy's thread next.

I only shoot handloads so this is disturbing to me.

I wouldn't be all that satisfied with the "have you unplugged it and plugged it back in?"  reply from Steyr.

A question for my own knowledge:  What specific problem does a new AUG have due to stiff new springs? Is it some kind of short cycling which turning up the gas overcomes until things work in?  This rifle looks as if it's pretty far from short cycling.

If I were closer to OP I'd help him out via process of elimination. I'd start with magazines, then swap the stock with a known good stock. If that didn't change anything then I'd look at swapping barrels next. If it's the barrel then I'd swap gas system parts. The last thing I'd swap would be the carrier, which I would highly doubt to have an issue.

My money is on mags or a stock that isn't quite right.

Nobody is infallible, but you can't particularly diagnose a mechanical problem over text message on Facebook... I think they gave good advice for what it was and the person giving the advice was not their gunsmith, that I can guarantee you.

Some new AUG's experience cycling issues with commercial ammo because recoil springs and hammer springs are very heavy. I've always had good luck with breaking an AUG in on 5.56, not off the shelf .223. Even then, I have some AUG's that eat weak .223 Russian crap all day long.

I'm sorry but I have to agree - that response from Steyr is unacceptable on several levels.  1000 rounds isn't enough to break in the springs?  They actually wrote that?

Not acceptable at all... I didn't even need a break in period and mine worked with every mag I got!

Call Steyr, thats an unacceptable solution.

You don't get double feeds from an undergassed rifle, that isn't the problem here.

That was a bizarre response from Steyr.

Are they saying we should be storing new AUG's with the bolt locked back to break in the recoil springs?

Looks like failure-to-eject aka short-stroke (unless OP confirms both rounds in this pic are live).
Most folks incorrectly called that a "double feed" when bringing one in for gunsmithing.

Steyr facebook advice wasn't too bad (other than the 1,000+ round break in lol).
Remove the gas piston and clean everything there, including the gas port (use pipe cleaner).
Switch to adverse.

If that doesn't do it, lock the bolt back using the notch in the receiver and let it sit a couple weeks, then try again.

Winchester white box is notoriously weak and sometimes inconsistent.
You may have to use ammo closer to 5.56 NATO strength until it's broken in thoroughly.

uh - no, those are two live rounds; not an empty that didn't eject.

If that's the case, then I suspect the stock wasn't made properly and something is at the wrong height.

I have had a double feed happen to me once.  I attribute it to shooting weak-hand (righty for me) and having the brass hit me in the face, and fall back into the ejection port, then when I tried to clear the brass from the port, it ended up double-feeding.  Not the guns fault, but damn it cost me a lot of time to clear that shit (was during a friendly match).

My money is on the stock.  Shipping back and forth to Steyr is going to be cheaper than burning ammo.

That's also one of the steps to follow when replacing the recoil springs.  They are that fucking strong

OP, try keeping the bolt locked back until you go shooting next

Just a note all magazines were purchased from 44mag website minus the green magazine

The rounds in the the malfunction are both live rounds so the rifle is not short stroking like it did in the break in period.

The malfunction occurred in the middle or beginning of the magazine from what I can recall.

Is the magazine supposed to have any play or wobble side to side or back to front?

How long is Steyr turn around time? I’d hate to have to wait for a couple months to get my rifle back.

How is their customer service?

Thank you

I have a new AUG that's only been fired ~300 times. Should I leave it with the bolt locked open?

I guess.  In general, no: "break in" is like 50-100 rounds, any more then that and someone needs to make stuff better.  Also, springs are worn in much more by cycling, then by being held compressed.  But that said, there soon will be a couple mechanical engineers signing-in saying compressing doesn't do anything to break in a spring - which may be true on paper, but in reality, I'm not so sure about that.  So sure, leave it compressed.  By some schools - you're supposed to leave the breach always open for safety anyway.

Frankly, you shouldn't have to "break" it in at all.  CZ uses (or used to use) a washing machine looking rig that they would put new production CZ-75's into.  They would spray oil in the rig, and it would spin around manually cycling and dry-firing the 20 or so pistols loaded into a few hundred times or so, to break them in for you.  If the AUG is really this sensitive to break-in (which I don't think it actually is); Steyr should be doing that.

They aren't particularly fast, but Herbert is pretty cool and does spend time, care, and attention to his work.  If there's a problem, and he can replicate it, I'm sure he'll fix it.  Also, he's got the bad-ass Austrian accent, that makes the whole thing worth it.  

As to play and wobble, obviously there will be some, but in mine, it's kinda minimal. I'm about to take my AUG to the range today, and plan on holding the magazine back, to see if I can replicate it.  No green-tip this time though...

Does it work? Yes - then leave it alone.

I will say the Steyr Gentlmen has been good regarding getting me the blueprint of the barrel threads and profile so I can have a custom Suppressor adapter made. He’s been very fast to communication and I will commend Steyr for that good customer service. I brought up several points made here and he elaborated on what he meant last night.

It makes zero sense that a "slow bolt carrier" would ever pick up 2 live rounds.

Either the rounds are popping out of the magazine or the magazine is sitting too high in the rifle causing the bolt to hit 2 rounds at a time.

Looks like in your case, the magazine is sitting too high.

I asked him to forward the information to the gunsmith but he was adamant that’s the cause so I’ll try his way than call if that fails

Bad magazines.  Replace and continue to train!

Here's the excerpt from my log postings - on my own testing today.


9/6/2018 update:  Fired 82 rounds.  No jams, but some test results.

Took the AUG out with Wolf Gold and with some 55 FMJ reloads.  


All runs were with just 5 rounds in the mags.  No jams, but did have one failure to lock back on the 42 round mag with the reloads (not that big of a deal).  The run was a team-building event with one of our new employees, so I was able to observe a little and do some tests.

Test 1: Pull back on the mag, to see if this causes a double feed.  So I grabbed the front of the mag and yanked back while firing.  This had no effect and gun shot 100% (well, so much for my prior theory that recoil rocking the mag back can cause double feeds).  
Test 2: Run the gun with several mags and see how she runs.  On one of the runs, I saw the mag went in and the round popped up somehow, just from magazine insertion.  It looked like this (done in a 42 for illustrative purposes - not the mag that did it):

Must have snagged something on insertion, or something.  No way in Hell is that going to load and cycle.  So.... rather than give up, I hit the bolt release button just to see what would happen.  Guess what, the bolt closed and chambered that round just fine.  We just looked at each other - Blew my mind.  "No way in Hell would an AR have been able to do that" the guy says.   I never would have thought that would have cycled in, but the AUG handled that fine.   What magazine was that anyway... I flip it over, and it's AUG Magazine #1.   Hmmm... that's interesting.

Test 3: still running it, I see the weird partial jump shown above happens again on me, while seating the mag (in fact, take a close look at the first photo, and you can see it).  What the Hell?   I flip over to see which of the 5 mags I brought it is... and it's AUG Magazine #1.   Riiight.

Test 4:  I insert magazines with vigor and all of them are fine, except one of them, which does a full round jump this time.  


Which magazine did that anyway?   AUG Magazine #1.

I'm getting a theory here.....   I'll post later the markings to see if anything suggests that one is from a different lot or fabrication date.

Total round count: 4749


--[End duplicate post]

Recall that the 1 time I experienced this was last weekend, and the Magazine that was being used when it occurred, was AUG Magazine #1.  Maybe it was the mag, maybe it was something else, but it's pretty coincidental.

Send me those defective mags for proper disposal.