Norinco M4 bolt not going all the way forward

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Roddy

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I recently bought a used 10.5" Norinco. I don't know too much about ARs. When I put the upper and lower together the bolt and carrier would not go more than about halfway closed. It got stuck right where I could see whole cutout in the side of the bolt carrier through the ejection port. I thought it was hitting the gas tube but I don't think it's that far forward. I played with it for a few minutes a d the bolt did go home once when I rode it home but then it got stuck halfway again and I couldn't get it closed.

I couldn't take the gun apart with the rear pin with the bolt only halfway closed so I pushed out the front pin and as soon as started to seperate the upper and lower the bolt slammed home. I tried switching the bolt group with my Colt and it worked fine in that and the Colt's bolt worked fine in the Norc.

What could be causing this? I can post pictures or a video tomorrow if my description isn't very clear. I tried googling it and the only problems I found described were failures to feed.
 
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Okay I took some pictures this morning.

Here is the rifle

enyt.jpg


Here is the upper, which I don't think is related to the problem but I could be wrong

oxzu.jpg


Here is the BCG that works in the Colt but not in the Norinco

pgt2.jpg


fu9h.jpg


Here is the lower that seems to stop the bolt from going all the way forward.

3p5h.jpg


And here is where the bolt stops, although last time I assembled I put it in the rifle it went about a half inch further forward so the cutout in the side was completely visible.

6pnz.jpg


5epx.jpg


I have a few more pictures on my phone and I can take more tonight if they will help.

What is causing this? It doesn't happen in my other AR and pulling the lower off lets the bolt go forward. When the upper is by itself the bolt goes home no problem.
 
Does the bottom of the carrier have a cut out? Your hammer is notched and could be catching on the FP or in the carrier cut out if it is damaged.
 
I don't know if the bottom of the carrier has a cut out. I can take a picture of it tonight. The previous owner sad he had no issues at all with this rifle so I thought I had messed something up assembling it.
 
I would talk to the previous owner... I have a feeling he knew about the issue and I would be leaving feedback saying rifle did not come in working condition.
 
I have mentioned the issue to the previous owner. He said it has never happened before.

On AR15.com I found someone who said that the firing pin on their unshrouded carrier was catching on their hammer. What would be the cheapest way to fix this?
 
Would taking some material off the hammer notch or firing pin collar make this better perhaps or would that just be asking for more problems? I was lead to believe that this gun had all the original internals so I don't understand why the bolt carrier and hammer are not compatible.
 
Try switching charging handles with your colt. I don't see any damage on the picture from the bottom of the upper looking in but your gas key looks like it's got a little wear on the sides but virtually no other wear.

When you put it together does it go together easily and rack back no problem then jam as it closes?
Does it feel like it's hitting something or is it wedging and jamming?

Also, I don't see the tip of the firing pin in the pic of the front of the bolt, is the firing pin installed correctly? It might be too far back. Just stand the BCG on the rear and tap it on the table, if the pin comes out put it in correctly. I'm not sure that would stop it from closing the way your describing, just looking for anything out of place and I seem to remember usually being able to see the tip of the pin through the hole on mine.
 
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I bet that BCG is an NEA. It's black like my NEA BCG, and it didn't fit nice in either of my norcs. Bolt issue, gun is fine if it works with colt BCG. I suspect the NEA BCG is slightly out of spec, as is the norc. Not enough out for some guns, but just enough in this case.
 
So you don't think that is a Norc BCG? The bolt comes back easily. No more difficult than my Colt. I will see if I can tap the pin forward. Could I do any harm using the out of spec bolt in my Colt AR? I don't like the idea of using a crumby bolt in my nicer rifle if I switch them. I will take pictures of the bottom of the bolt tonight. If its not a Norinco bolt I will be speaking to the seller again.
 
My new NEA bolt carrier group was exactly the same in two norc AR's. It would stick when going forward. It seemed to me, that the head was slightly big for the AR to engage the lugs all the way. After working it back and forth a bunch of times, it got better in one, but was still pretty snug. My CQA rifle came with a greyish BCG, my NEA and yours look black.
 


The cut out in the bottom (3rd from left) is meant to allow the FP catch the notch in the notched hammer if the hammer does not properly engage on the disconnect. This is to prevent doubling or burst firing - particularly on modified guns.

When these are copied by other manufacturers or used mismatched in franken-guns they cause stoppages. The firing pin is also meant to have a smaller diameter flange. A normal firing pin may catch on the hammer and also cause stoppages.

The normal FP flange diameter is .370 " , The modified one should be .330 ".

Post a picture of the trigger mech looking down with the upper remove and also the bottom of the carrier.

Also check your gas key and make sure it is straight and secure and the hole in the end is round and not dented in.
 
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5440fight said:
My new NEA bolt carrier group was exactly the same in two norc AR's. It would stick when going forward. It seemed to me, that the head was slightly big for the AR to engage the lugs all the way. After working it back and forth a bunch of times, it got better in one, but was still pretty snug. My CQA rifle came with a greyish BCG, my NEA and yours look black.
Click to expand...

He said it engages the lugs no problem when the upper/lower are seperated. From the pics it's not going far enough for it to be a problem with the locking lugs.

I definitely think the previous owner knew about this. Defintely give him some negative feedback if he continues to deny it and won't give you any details about what he's done to the rifle.

If you have time off tomorrow before 4:00 I could have a look at it with you. I have an appointment in the west end of Edmonton at 6:00 but am off the rest of the day.
 
Don't turn this into an EE rant. Enough about the previous owner, etc.

Please keep it on topic.
 
I don't think the previous owner had any problems and I don't think he kept anything from me. I dont blame him for te problem. Its a used made in China rifle, these things happen. I still think I may have damaged something assembling the rifle.

I tried mating the carrier and lower receiver. The hammer catches on both shoulders of the firing pin.

Here is the bolt

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And here is another shot of the hammer

pf4d.jpg


I believe switching out some of these parts will fix it. In the meantime my only concern is could this bolt carrier damage my SP1 and could this gun damage my SP1 bolt carrier? They seem to work swapped out so is there any problem shooting the rifles like that?
 
C77 said:
Don't turn this into an EE rant. Enough about the previous owner, etc.

Please keep it on topic.
Click to expand...

Telling him to contact the previous owner to get the truth out of him and to leave appropriate feedback for him if he continues to deny knowledge of the problem to warn the of us not to deal with someone selling their problems on the EE is far from turning this into an EE rant.
Almost all posts have been on topic with a couple minor exceptions.

Roddy, PM me if you have time off tomorrow and want a second set of eyes to try to figure it out.
 
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