FA Uzi firing FA when set to Semi

[ratski]

Had an interesting problem.
And before anyone goes off on a "if it fires fully automatic on semi, you have an illegal machine gun" this is a Registered, Transferable Fully Automatic legally owned and "papered" Vector Uzi.

That being said....

I've had a few instances where I have had this set in Semi Auto and gotten a burst fire.
I've had the gun for years without a hiccup.
Same top cover
Same magazines
Same general ammunition (WWB and/or S&B)

FA fire stops when you let off the trigger.

I'm guessing a worn part. Just wondering if anyone can point me in the proper direction to look see.

And thanks in advance to those of you who will offer to take this "defective piece of junk off" of my hands. To paraphrase George Bush 41 "Not gonna happen."

Thanks

Dave

 

[RickN]

Had a friend years ago that had the same problem, said it was a worn sear. I have never owned one so can not say if that is correct or not but might be worth checking.

 

[Fyrtwuck]

Hey Dave,

I agree that it's probably a worn sear or possibly the selector isn't working properly. UZI's are built like tanks and hard to break. IIRC the sear is inside the trigger group in the lower. Also, IIRC they have one for rent at Firearms Solutions and can probably fix it for you or show you what's wrong.

Unfortunately, I don't think Vector Arms exists anymore after their legal problems with the Feds and Dept of State. They were a company with a VERY good reputation of quality and customer service.

You may be able to find what you need here.

https://www.gunpartscorp.com/search#query=Imi Uzi

 

[CAR-AR-M16]

I would look for rounding off of the edges on the sear and the notch in the bolt that the sear engages. Also, might consider replacing the sear spring, it may be getting weak with old age/use (just like me )

 

[Fyrtwuck]

Did you get it fixed?

 

[rocketman]

If its not a short stroking problem its a trigger/sear timing issue. The little block pinned to the front of the trigger (I call it the disconnector)must fall off (release) the inner sear tabs at the same time or preferably very shortly after the sear releases the bolt. That way the sear can move back up and catch the bolt after the first round. The mechanism relies on the finger pressure applied to the trigger causing a sudden movement backward in the trigger after the bolt is released and trigger pull lightens. This tells me Uzeil designed semi auto to be fired like a shotgun not a varmint rifle. If this is the problem, it should fire single shots if you pull the trigger quickly and fully to the rear...and fire doubles when you squeeze the trigger slowly.

To improve it:
Try replacing trigger, disconnector, and/or sear. One might be worn down in any of the wear spots which cause this.
Check top cover to bolt clearance. If the top cover allows the bolt to sit too high this can cause it. Bend cover as needed.
Move grip housing closer to receiver if it is loose or sitting low(bend front housing tab down or check for rear pin hole wear).
Put a shim under the arm on the front of selector lever that the disconnector trips on in semi mode.
File tabs on sear(avoid !!!).
Jerk trigger, don't squeeze.


The opposite problem is when the trigger block falls off the sear before it releases the bolt. You would hear a click only then have to pull the trigger and second or third time to get it to fire or possibly not at all. These problems apply the semi auto closed bolt guns too.