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I've been fighting a failure to eject problem with my SIG556R.  I finally have the problem identified but stumped as to the solution.

 

When I place the cartridge in the bolt by hand, making sure the extractor is engaged, and then close the bolt, it extracts and ejects every time.  When I feed from the mag it fails to eject about half the time.  I found that when I chamber a round from the mag and then pull the bolt back slowly the extractor is just sitting on the rim, and not engaged.

 

Same thing happens if I drop a round in the chamber and then let the bolt slam on it.  Extractor doesn't grab the rim.

 

What is the fix for this?

 

I'm wondering if it's a headspace problem...  But more likely an extractor problem.

 

The extractor pin is staked on both ends, so I'd have to drill it to get it out.  Don't plan to do that.  I did read something on the web that the extractor is supposed to be staked on one end only. 

 

I've also tried with Wolf, Tula, GT, and Hornady.  Makes no difference.  I don't have any brass case and don't give a shit if it functions with brass or not since I don't plan to use brass ever.

Edited by Darth Saigus
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Any mag.  The poly that came with it.  Surplus euro.  New Yugo.  Same thing if I load the round in the chamber and then close the bolt.

 

The problem isn't the mag.  It's the extractor not popping over the rim fully when the bolt closes.  This rifle doesn't have controlled feeding so the extractor has to pop over the rim when the bolt closes.

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Drop the round into the chamber, let the bolt fly, let us know if the round is pulled back out.

Double check that there is no crud stuck in the bolt face.

Sounds like there might be a bur on the extractor where it catches on the rim.

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Could it be possible that the rounds are feeding from the mags at an extreme angle, thus causing the bolt to slow down to the point that it fails to

totally close or catch the round?  Does this happen with all ammo (brass, steel, hp, fmj)?

Edited by DLT
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Bolt face is clean.  Extractor has no obvious defects.  Inspected with 10X magnification.

 

I also hosed the bolt with brake cleaner and worked the extractor to make sure everything is clean.  Re-lubed.

 

When I drop a round in the chamber and let the bolt go home it does exactly the same as feeding from a mag.  If I pull the bolt back slowly the case is being held but only on the edge of the rim, not behind it.  If I pull the bolt back fast the round is extracted but not ejected.

 

This same behavior when firing.  The empty is not ejected.  Doesn't even stovepipe.  Sometimes the empty is jammed back in the chamber.  When that happens I have to use a rod to tap it out, but it's not stuck.  Only a light tap is required to free it.  The extractor would pull it out easy if it was actually grabbing the rim.

 

But if I put the round in the bolt by hand with the rim behind the extractor and pull it back fast it ejects across the room.  Same thing when shooting.  Ejects 20 feet.

 

It feeds fine from any mag.  The bolt fully closes.

Edited by Darth Saigus
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It's a gen 1.  Bought 2nd hand.  It has never ejected since I've owned it.

 

I'll send it back to SIG (who have already had it once for the recall but obviously didn't bother testing it after they "fixed" it) if I have to, but if I can fix it myself (as I did with the wife's Walther PK380) then I will.

 

I want to love this rifle.  I will love it if it works right.  But my love for SIG is seriously diminished for them putting out a turd like this to begin with.  The gen 1 was just a pile of crap.  No steel mags?  No steel ammo?  Are you fucking kidding me?  It's a 7.62x39. 

 

They fixed it so it can run steel mags and steel ammo but obviously didn't bother checking that it actually worked.

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It sounds like the bolt face is to deep, lugs sticking out to far.

Any way to measure the round after you drop it into the chamber,

measure what is sticking out.

Them put a round into the bolt and measure how far it sets back in the the bolt.

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Getting measurements precise enough to be meaningful, probably not.

 

As I said in the op I was concerned about headspace but the cases look fine.  No indications of excess headspace.  Of course the only way to be sure is to use a no-go.  I don't happen to have one of those.

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The round in the chamber is .125 give or take a couple thousandths.  For the bolt the measurement is .118 deep.

 

One thing I noticed when I was taking these measurements is that the extractor claw is so close to the bolt face that it won't pop over the rim when the case is flat against the bolt face.  The only way to get the rim under the claw is to put it under and then tilt the case into place.

 

It definitely looks like the extractor is out of spec.

 

I was reading a post on another forum about a guy with a 556 that had the extractor pin staked at both ends.  Turns out the pin was bent and binding.  Mine is not binding but maybe it's bent and pulling the extractor toward the bolt face.  It wouldn't take but a couple thousandths to make it not work.

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The round in the chamber is .125 give or take a couple thousandths.  For the bolt the measurement is .118 deep.

 

One thing I noticed when I was taking these measurements is that the extractor claw is so close to the bolt face that it won't pop over the rim when the case is flat against the bolt face.  The only way to get the rim under the claw is to put it under and then tilt the case into place.

 

It definitely looks like the extractor is out of spec.

 

I was reading a post on another forum about a guy with a 556 that had the extractor pin staked at both ends.  Turns out the pin was bent and binding.  Mine is not binding but maybe it's bent and pulling the extractor toward the bolt face.  It wouldn't take but a couple thousandths to make it not work.

You found it, now for the fix, remove the claw, get a diamond stone and take a bit off till it will work.

post-37682-0-56228000-1398473891.jpg

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My wife's gun had similar issue, I took a junk brass, mothers mag polish and a drill, wrapped the brass with polish, stuck it in the drill, hooked it under the extractor, and spun it a bit.

Now this is a good trick! One I will remember.

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Yep, that same thought occurred to me about using polishing compound and an empty case.

 

I can't remove the extractor.  The pin in staked on both ends.  I'd have to drill it out and then I'd need a new pin and I wouldn't have a way to properly stake the new pin.

 

OK I did the polishing compound with an empty case.  Now the extractor will pop over the rim sometimes.  Sometimes not.  Guess a little more polishing and maybe I'm good.

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Since I wasn't too excited about the wear on the bolt face from the polishing compound I decided to use a jewelers file to finish the job.  Just a few strokes and now it ejects reliably by hand. 

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  • 2 weeks later...

Well I found that after I fixed the FTE problem, I still had a FTF problem.

 

The bolt just wasn't going back far enough to pick up a round from the mag.  So I opened up the hole in the gas plug a step at a time until I got reliable feeding.  I wound up at .084 on the primary and .089 on the adverse.

 

So for the first time since I got the rifle it will run a full mag.

 

I also got my wife's PK380 running reliable but it ejects straight into the shooter's face.  That gun is going bye bye.  And I won't be thinking of buying another Walther.

Edited by Darth Saigus
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So for the first time since I got the rifle it will run a full mag.

 

I also got my wife's PK380 running reliable but it ejects straight into the shooter's face.  That gun is going bye bye.  And I won't be thinking of buying another Walther.

Awesome news Saigus!

 

My friends Walther 22 pistol soured me on them.  Now with your experience, I doubt I'll ever touch another.  Not unlike your Sig, it pisses me off when manufacturers sell this crap.  It's not like these are toys.  You are supposed to be able to trust them with your life.  The 22 semi auto pistol thing is full on retarded

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Funny about the Walther. My P22 eats everything for some reason defying all the ill write ups about them. It even cycles sub sonics without the can. CCI birdshots are 50/50 though. Glad you got the Sig running better.

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Glad to see you got this fixed Darth Saigus, damn shame the extractor is staked on both ends by Sig. Seems fucking dumb as complete bolt disassembly is often required for thorough cleanings from time to time!

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