Non-stop jams in my transferable IMI Uzi

[jscowboy]

I bought a transferable IMI Model A which was converted to full auto from semi. It has a full auto (open) bolt, but still uses the semi auto barrel. Since I bought it, I have been experiencing non-stop jams, sometimes as many as 10 jams in one magazine.

I tried thoroughly cleaning it - didn't change a thing.
I tried using different ammo, specifically 124 grain - hasn't helped.
I tried using different magazines - did not work.
I tried swapping out the spring assembly -did not help.
I tried switching the barrel - did nothing.
I switched out the converted semi-auto fire control housing for an original one off a full-auto IDF parts kit - that DID seem to help (to some degree).
I tried swapping the bolt for the one that came with my parts kit - it would not function so I went back to the original bolt.

I brought the Uzi to an experienced machinegun builder who specializes in Uzis and he took it apart and couldn't find anything wrong with it.

The guy I bought it from insists that he never had any jams in all the 25+years he owned it. I tend to believe that because I managed to shoot it while it was in jail with the Class III dealer waiting on the Form 4 to get approved and we had no jams shooting through almost 1000 rounds. We were using cheap Russian steel case ironically.

I am simply at a loss and don't know what to do, as nothing I try seems to fix the underlying issue. Maybe somebody here has some idea as to what might be wrong and what I can try to fix it?

Thanks for your help!

 

[Member13]

But what exactly is the jam? FTF, FTE, SP, ?

 

[mike]

Is the barrel restrictor ring still on the feed ramp? Also is the trunnion drilled out for a submachine gun barrel or a semi barrel?

 

[TSPC]

Here's some good info on possible problems with the Uzi.

 

[jscowboy]

But what exactly is the jam? FTF, FTE, SP, ?

There are several different types of jams occurring. The most common is having a chewed up shell getting stuck behind the bolt. I am also having double feeds and stovepipes galore.

 

[jscowboy]

Is the barrel restrictor ring still on the feed ramp? Also is the trunnion drilled out for a submachine gun barrel or a semi barrel?

Yes, the semi-auto barrel restrictor is still on the feed ramp. I'm not 100% sure about the trunnion, but I believe it is also the original semi.

 

[MontanaRenegade86]

So it worked perfectly until you got it home, and now it doesn't?

What brand of barrel are you using? IMI? Green Mountain? Vector?

Have you pulled the extractor and cleaned the hell out of it and the channel it sits in?

Is your ejector tight?

 

[jscowboy]

So it worked perfectly until you got it home, and now it doesn't?

What brand of barrel are you using? IMI? Green Mountain? Vector?

Have you pulled the extractor and cleaned the hell out of it and the channel it sits in?

Is your ejector tight?

The Uzi came with 2 barrels that are unmarked, so I am unsure of their manufacture. My assumption is they were IMI 16 inch barrels that were cut down and recrowned when the gun was converted. I also tried a Green Mountain barrel that I took of my Uzi SBR and that one didn't change anything. I did not pull out the extractor. Think that might be the issue?

 

[MontanaRenegade86]

The Uzi came with 2 barrels that are unmarked, so I am unsure of their manufacture. My assumption is they were IMI 16 inch barrels that were cut down and recrowned when the gun was converted. I also tried a Green Mountain barrel that I took of my Uzi SBR and that one didn't change anything. I did not pull out the extractor. Think that might be the issue?

I'd give the extractor and channel a good cleaning. When I got my registered bolt, the channel was absolutely caked in crap.

I took my Uzis out a few days ago. My bolt gun ran perfectly, but my semi Vector was nothing but trouble. I had a lot of the same symptoms you are having. I think it had something to do with the Vector barrel. I didn't bring my spare barrels out to the range, so I couldn't verify if that was the issue. All I know for certain is that I wanted to wrap that Vector around a rock. The air was blue with profanity.

 

[sweersa]

Good luck! I know how frustrating a malfunctioning gun can be. I have a USP 45 full size, bought new that has always given me intermittent fits with anything except blazer aluminum cased ammo or +P brass. Been to HK twice, and a third party after HK and still has issues so I just keep hot ammo in it and run it. My USP 9mm full size and HK45C are fine.

Hope you get it figured out so you can enjoy it without the frustration plaguing what should be a fun experience!

 

[Member13]

So I take it your bolt is not the registered part......has the bold been modified for the semi feed ramp?


I have a Group Industries bolt that is clearanced for the semi auto restrictor feed ramp.....I can dig it out and as long as you cover postage it will be easy to send to you for testing. Like $10 each way and if it works for you we can talk about price/trades

 

[ScottinTexas]

I have a Group / Vector FA that has provided me a learning opportunity similar to yours.

I can't opine on your specific situation, but offer this:

1. Restore everything to the condition and ammo that worked flawlessly, then change one thing at a time.

2. Remove the recoil spring and tilt the bolt-inside-the-receiver looking for hang ups. You need to make sure the top cover clearance is acceptable; not too tight, not too sloppy.

3. Green Mountain barrels do NOT have the same chamfer on the outer edge of the breach end that other barrels have. The FA bolt tends to hit the breach end and you get light strikes that fail to ignite.

4. Make sure you KNOW the reason for the malfunction. Is it fail to feed? Fail to extract? Fail to eject?

5. Use IMI / Milsurp magazines until you figure it out.

6. Make sure your barrel nut is tight and the teeth not worn.

Good luck.

 

[Dirk Hawthorne]

my recent jamming problem was solved by changing the extractor for a new one.

plus using ammo that was hotter. my handloads were too weak.
i figured this out by process of elimination. changed one thing at time.

 

[ScottinTexas]

?

 

[K2]

Hi,
As usual it is hard to tell from here. Change the top cover? Either way, make sure the gap is set.

Enjoy,

K2

 

[Redhed]

Is your ejector solid or wiggly? Mine got a bit loose once and caused similar issues. Hammered it back down and good for another 100,000.

 

[Dirk Hawthorne]

Is your ejector solid or wiggly? Mine got a bit loose once and caused similar issues. Hammered it back down and good for another 100,000.

When I swapped out my extractor, the new one definitely fit tighter. But the old one looks fine.

I'll give it a bend and see if that fixes it.

 

[Redhed]

Extractor is good to check. But watch this about the ejector and make sure it’s tight.

 

[scotty57]

Sounds like a tight top cover. seen this on a lot of Group ind. guns bend down the little noze on the front of the top cover with a plier bit at a time till it shoots well......

 

[ironriver]

There are several different types of jams occurring. The most common is having a chewed up shell getting stuck behind the bolt. I am also having double feeds and stovepipes galore.

That really sounds like an ammo issue... I assume you are using brass cased FMJ correct? The other thing if not that and I know you said you changed ammo could be the top cover .. converted Uzi's are 50/50... but the fact that it was OK in NFA jail really makes me think its ammo related