Failure To Eject . . . Any Tips Please?

NLGT

NLGT

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Just got my new to me PSA 7.62x39 Upper today, of course ra to the range to try it out. Rifle will not fire more than one round without jamming because of a failure to eject. Sequence:

1) Load mag with bolt open.
2) Chamber round
3) Fire
4) Bolt strokes back with spent round, however once it reaches the back stroke, it does not flick it outward, it kind of just drops it.
5) Bolt attempts to re-chamber a fresh round from the mag, however it's stopped when the spent round prevents it from going farther ahead.
6) Jam.

Being this is my first pistol length AR, I was thinking it's a buffer issue (Running a Spikes T2, which should work). Tried a few more rounds, same result every single time. After 10 tries, I called it quits and began to pack up.

However, I tried to chamber by hand and just cycle the charging handle manually, and found I was getting the exact same result. The bolt will haul out the spent casing, but once it gets to the point where it should be flicking it out, it just drops it in place.

To confirm my thoughts, I tried with my Spikes 10.5 upper in 5.56, and it throws them out with force every single time when manually charging.

So, I took a look into the extractor. Nothing obvious, but I did have an extractor spring upgrade kit in the safe, so I installed it. Still the same result. The small cylinder in the bolt face which should put pressure on the spent casing to flick it out seems to be in good order. There's a fair amount of pressure on it, but you can press it in and out. The extractor claw itself looks good. And yes, the bolt is installed properly (not backward)

Can anyone help me out? I'm at a pretty good loss here.

A picture below of the jam:



Thanks in advance!
 
Tried removing the rubber donut on the extractor spring, no change.

However, I did have a box of MFS Non Corrosive ammo here, and that ejected fine through manual charging. Previous ammo used is Dominion Non-Corrosive.

Is it possible she just won't cycle the Norinco stuff due to tolerances?
 
Could you have a gas problem i.e. short stroking? Check that the gas block hole is aligned and that the block is tight. Unless the extractor is bouncing off the rim due to insufficient tension there isn't much to go wrong with and AR extraction cycle.
 
sounds like a short stroke to me.
this is a pistol length gas system upper mated with a carbine buffer spring and buffer?

a spikes 10.5 will still be a carbine system hence why it runs properly.

why not try it with a bunch of different buffers of different weight.
 
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Correct, it`s using the same setup I use on my 10.5, a Spikes T2 buffer. I don`t have any other buffers to try on hand at the moment.

I`m led to believe it`s not short stroking though, as even when I fully stroke it back via a manual charge, it still fails to eject with the Norinco ammo. I would think if it`s solely to do with the buffer weight/spring used, then me fully stroking it should net a full ejection each time - am I looking at that right?
 
NLGT said:
Correct, it`s using the same setup I use on my 10.5, a Spikes T2 buffer. I don`t have any other buffers to try on hand at the moment.

I`m led to believe it`s not short stroking though, as even when I fully stroke it back via a manual charge, it still fails to eject with the Norinco ammo. I would think if it`s solely to do with the buffer weight/spring used, then me fully stroking it should net a full ejection each time - am I looking at that right?
Click to expand...

you got some mfs or some full brass 762 laying around?

mfs has a different lacquer, full brass no lacquer
 
^ As above, MFS steel case seems to eject fine, however I never had it at the range today to confirm proper firing order.

Really hoping it's just a break-in thing, i have a ton of that Dominion/Norinco non-corrosive, it'd be a sin if they new toy can't chew it.
 
Can you take a picture of the face of the bolt is the ejector there?
It sounds like it's missing or not working, extraction is fine but the piece that kicks the casting out isn't working
 
^ Yes, lots of forward pressure there. A little bit difficult to compress but it'd able to go in flush with the bolt face with some effort. it returns to the original position no trouble.

It seems like with the Norc ammo, for some reason it can't throw it to the side.
 
I think that you have a faulty extractor that might be bouncing off the lip of the cartridge near the end of the extraction cycle. The extractor has to have a good grip on the cartridge-base even during the first 10-15 degrees of rotation of the case when the case mouth clears the chamber.

If the extractor has just enough grip to pull the cartridge free of the chamber when the case-base is square to the bolt face, but releases as soon as the case clears the chamber, I think you would see these types of failure to eject.

maybe you can test this by pressing a case against the bolt-face to see how much you can tilt the case towards the extractor before it releases. It should hold until the case is 30-35 degrees from the bolt axis.
 
This is a foolish way I'm testing this, but in comparison on a degree-marked circle on my TV, it looks like it's letting go of the case around 25 degrees (This is me eyeing it in haha) It doesn't seem to have a difference using an MFS or Norc case. However, I do notice that the extraction lip on the case of the MFS is slightly thicker than that of the Norc - might have something to do with it.

So, being the case - what now? I have already replace the extractor spring with the upgrade kit. Try a new extractor itself I suppose.

Now, where would one find an extractor for a 7.62x39 bolt?

Thanks again for all the help guys, certainly appreciated!
 
If you have eliminated extractor and buffer issues you could try changing to an adjustable gas block. Short barrels are extra susceptible to cycling problems. This is also the exception where a gas piston conversion may be beneficial.
 
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Firehoser said:
If you have eliminated extractor and buffer issues you could try changing to an adjustable gas block. Short barrels are extra susceptible to feed problems. This is also the exception where a gas piston conversion may be beneficial.
Click to expand...

Thanks for the suggestion, however as mentioned before, feed isn't the problem so much as the ejection. Even when manually charged, the rifle still fails to eject properly and lays the spent case on top of the fresh round. This should take the gas system out of the equation by my thinking.
 
Sorry I corrected my post. I meant to say cycling not feed problems. Do you have a spare bcg or could you borrow one from a friend? If it works you can compare the two and see if there is something off on the original.
 
^ Good point. I don't know anyone locally with a 7.62x39 bolt, but I'll have to see if someone has one buried away. This rig needs to get up and running, lots of ammo to eat.

As an aside, very glad I went with 7.5". Even though I really couldn't run it well today, the compact-ness of it really feels great while holding it!
 
NLGT said:
This is a foolish way I'm testing this, but in comparison on a degree-marked circle on my TV, it looks like it's letting go of the case around 25 degrees (This is me eyeing it in haha) It doesn't seem to have a difference using an MFS or Norc case. However, I do notice that the extraction lip on the case of the MFS is slightly thicker than that of the Norc - might have something to do with it.
Click to expand...

That sounds like there should be enough retention to eject. Weird. When you slowly, manually extract a round is the case trying to flip out the ejection port? Put your finger against the case to hold it in line with the bore while you slowly cycle the bolt and feel how much pressure is torquing the case.

If there is hardly any pressure/torque then the problem might be a weak ejector spring. This is reaching a bit since I've never seen this be a problem in an AR.

Is the bolt brand new?
 
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