[flesheatingvirus]

This happened 4 separate times at the range. It is NOT an accidental bump fire. Firm to the shoulder, trigger held back firmly. I am 100% sure it fired 2 rounds.

It’s a fairly new A3/M1. What parts should I check out?

 

[Zudrick]

Trigger pack, can you post pics? It’s weird if held back to only do two and not empty the mag. When you take a shot did you immediately release the trigger or did it happen without releasing the trigger?

 

[flesheatingvirus]

To help diagnose and eliminate the possibility of a bump fire, the trigger was held back until it stopped firing, whether that be one or two rounds. It was fast, too. I almost had to go by sound because the two rounds fired consecutively so quickly. My shooting buddy also confirmed that it happened several times with both of us shooting it.

By the way, I also have a Rat Worx sear installed. I can possibly get some photos tomorrow.

 

[flesheatingvirus]

I examined the disconnector and the hooks on the hammer for possible damage/slippage. The surfaces look good to me- no visible wear and still sharp edges. Also this AUG has <500 rounds through it. It is still a bit stiff. I wouldn't say it's broken in yet.

 

[Zudrick]

Sorry I wasnt around my Aug when I posted earlier. First place I always look if there is multiple rounds issue is here on the surfaces, although only two rounds is unusual for that location. After that if good I would look at the 2020 sear and take it out, inspect, then reinstall. Then test again. It’s hard to see the components on the 2020 sear but a bad instal could cause issues if it’s not properly aligned. While out I would take out the receiver. Here I would check everything lookes good with recoil and the pressure is right, also just look at the trigger bar, although that would be odd for an issue. Finally I would take out the firing pin and make sure again everything is good with the bolt / pin. Chase is a Steyr armorer and if he has different recommendations I would go with what he says. That said I have seen some send multiple rounds down range and they tend to have damage around these two parts below in pics. If you need videos or pics of any of the other parts let me know.

 

[flesheatingvirus]

Thanks for the info! Those two circled parts (disconnector and hammer hooks) were the first places I looked for issues. I'll still take out the sear to look over everything in greater detail. I just had the bolt taken apart for cleaning, but I'll check that over anyway.

Is there a decent guide to taking out the trigger bar or disassembling the trigger pack? The original owner installed the new sear, so I'm not as familiar with the process.

 

[Zudrick]

I just used the ratworks installation video they made although the lighting on it isn’t the best

 

[flesheatingvirus]

Following the video, I stripped the trigger group. I didn't see anything out of place or damaged. After reassembly, it seems to function normally.

 

[silentheart]

I have similar set up in my Aug. yes, you will get 2 inconsistent round burst if.
1 you adjusted the sear spring
2 using hotter 556 ammo
3 piston setting to adverse
4 the wonderful ratwork 2020 sear
Any 2 combo and 2020 sear will get you 2 round burst.

 

[P0H0]

3 piston setting to adverse
4 the wonderful ratwork 2020 sear

So the Ratworks sear and adverse gas setting will result in a double burst occasionally or more often?

 

[silentheart]

So the Ratworks sear and adverse gas setting will result in a double burst occasionally or more often?

More often, correct.