Full Auto Uzis questions, regarding IMI conversions

[preferglock17]

I have been looking into acquiring a NFA Uzi SMG.

I've been reading what I can for awhile and really aren't sure if I would prefer an IMI conversion or a Group Industries. Both seem to have possible problems.

One question I have is if I buy an IMI conversion that still has the barrel restricter ring, will that prevent the use of a standard Uzi SMG bolt ? I am not sure 100% on that, that would be a limited factor. Unfortunately most Uzis I've seen for sale online lately seem to still have the barrel restricting ring.

I know you definitely want the rear blocking bar removed.

Any advice, appreciated.

 

[slimshady]

The ring is larger than the stock opening on an OEM full auto bolt, you either have to open up the area of the bolt that telescopes over the bbl or remove the ring. Removing the ring by machining it down into a FA spec feedramp is probably the best solution, allows you to use regular FA spec bbls and bolts. The semi auto trunnion also has a smaller inner diameter to prevent a FA bbl from fitting, you can ream it out larger or turn down a FA spec bbl to fit. Or you can just machine the top of the ring off, it will still require a semi spec bbl with the smaller chamber end to fit the remnants of the ring, but it allows an unmodified FA bolt to pass over it.

OTOH, it does help stabilize the rear of the bbl some so it does have it's advantages.

 

[preferglock17]

I found one that seems to have a registered sear. I didn't realize there was registered sears, thought it was just registered bolts or receivers. I know I do not want a registered bolt, not sure what to think of a registered sear but really would prefer a registered receiver.

Any imput ? I saw the form looked like both the sear and receiver were listed and had two different serial numbers.

 

[amphibian]

The ring is larger than the stock opening on an OEM full auto bolt, you either have to open up the area of the bolt that telescopes over the bbl or remove the ring. Removing the ring by machining it down into a FA spec feedramp is probably the best solution, allows you to use regular FA spec bbls and bolts. The semi auto trunnion also has a smaller inner diameter to prevent a FA bbl from fitting, you can ream it out larger or turn down a FA spec bbl to fit. Or you can just machine the top of the ring off, it will still require a semi spec bbl with the smaller chamber end to fit the remnants of the ring, but it allows an unmodified FA bolt to pass over it.

OTOH, it does help stabilize the rear of the bbl some so it does have it's advantages.

This is discussed in the library.
http://www.uzitalk.com/reference/pages/FAconversions.htm
I wrote the original conversion article and the picture below I took and of some of my RR IMI conversions.
Visual helps to expand on what poster above mentioned.
The UZI in middle accepts an unmodified SMG bolt but still requires a barrel that is turned down to fit in the ring which does now provide 3 points of support but then you have to use barrels that will fit it.

 

[slimshady]

I found one that seems to have a registered sear. I didn't realize there was registered sears, thought it was just registered bolts or receivers. I know I do not want a registered bolt, not sure what to think of a registered sear but really would prefer a registered receiver.

Any imput ? I saw the form looked like both the sear and receiver were listed and had two different serial numbers.

Most likely the registered sear is permanently "married" to the receiver it is installed on. On a full size UZI you have to remove the blocking bar to get a FA spec bolt to fit, removing the bar makes it an MG receiver. The sear by itself won't make the gun FA reliably with a semi bolt so the receiver was likely modified to accept the FA bolt. Back in the day ATF wasn't so strict on how things were done and many makers registered the "wrong" part. With the bar removed it should be a registered receiver, not a sear. To fix this, the sear can only be used in that receiver. You can add caliber conversions and the like, but the registered part is the sear so easier to damage/wear out than a true RR.

 

[preferglock17]

Yeah that is kinda what I thought. Yes I believe the sear is married to the gun. Both are listed on the form. Both have different serials. I am familiar with the blocking bar and removal. I don't know if this gun has the blocking bar removed but since the photo of the side shows a bolt that is not cut I would assume the blocking bar must be removed.

I am not real interested in it I don't think, with the sear issue.

 

[Renegade]

Yeah that is kinda what I thought. Yes I believe the sear is married to the gun. Both are listed on the form. Both have different serials. I am familiar with the blocking bar and removal. I don't know if this gun has the blocking bar removed but since the photo of the side shows a bolt that is not cut I would assume the blocking bar must be removed.

I am not real interested in it I don't think, with the sear issue.

Avoid a gun that is not properly registered.

 

[preferglock17]

It is registered. Both sear and receiver on the form.

I think what you are saying is avoid a sear registered gun and only go for a bolt or receiver registration as that would be the proper way of registering an Uzi ?

 

[MGMAN45]

As long as the blocking bar is removed the rest can be brought up to factory spec.

 

[preferglock17]

Yes I know that but the sear and receiver both being registered concerns me. Seems like sear could break a lot easier then the receiver.

 

[mike]

I had a sear break.

 

[pmf]

I had a sear break.

So did I. Gun would shoot a couple of rounds after I let go of the trigger. Kinda scary. It was easy to fix.

I wonder if the sear on that registered receiver gun has a serial number. The OP said there's two numbers on the form. That seems really odd. If it does, and I owned that gun, I'd replace the registered sear with one from a parts kit until I was ready to sell the gun.

 

[slimshady]

Unfortunately ATF would consider using a replacement sear as "divorcing" the legal combo, not allowed. The sear is the registered conversion device, and the receiver it is attached to is only allowed to be used with that sear, and of course you can only use that sear with that receiver. If the receiver lacks the blocking bar, which from the description it does, he technically now has 2 machine guns, one conversion device and a SMG spec receiver whenever the two are separated beyond temporary things like field stripping for cleaning.

 

[pmf]

I'd still do it and risk the Sear Police. Cause if you break that sear, you're SOL.

 

[slimshady]

I'd still do it and risk the Sear Police. Cause if you break that sear, you're SOL.

Someone not concerned with the legality could just as easily have any number of surplus sears engraved to match the original. It's not like they were ever serialized like a receiver, one is pretty much the same as another. But that would be wrong even though getting caught would be extremely unlikely unless someone found a duplicate.