Monday, July 22, 2013

Homebuilding an Uzi carbine.

I've built a good number of firearms over the years for my own enjoyment, some have worked well, and others have been less than reliable, but still fun to build and shoot. With that in mind, I've got some new stuff on the build list.

Latest among the list of fun projects is an Uzi. I actually built most of another kit over the last 4-5 months, but have just now gotten another kit and enough pictures together to post about.

First, a little background on the Uzi.......
You can simply go here and read up on a little info on the Uzi, and come back here when you're done. Now, like most pistol caliber machineguns, the Uzi is an open bolt blowback gun, which presents the usual problems for homebuilders like me. This means that I have to convert the gun to closed bolt only, and ensure that it can never be readily converted to fire in fully automatic mode, usually entailing a complete rework of all the internals of the gun.

I can't think of anyone, pro gun or not, who does not recognize the lines of the Uzi. The Uzi has been made famous by being featured in a number of movies, and has proven itself in real life through use by the IDF for a number of years, as well as several other countries' armed forces, including our own. The sheer cool factor alone is enough reason to own one, for me. Unfortunately, most of the current semiauto Uzis on the market are fairly pricey, and I won't even bring up the cost of buying a NFA-registered machinegun. This leaves only one way for cheapskates like me, and that is to build my own.

So, we start out with a demilled full size Uzi receiver. This has been torch cut to BATFE specifications, and is no longer a firearm. Because it is only scrap metal in the eyes of the BATFE, I can rebuild it into a semiauto configuration and it will then count as a US-made part for the purposes of 922r.
This is a mostly-complete Uzi kit that came in the mail the other day. It looks pretty hacked up, sure, but we will fix that in due time.
Mind you, not all the receiver pieces are present. I will have to either fabricate a few, or use pieces from other demilled kits, such as the ones that Apex sells. For what it's worth, I have no connection to Apex other than just being a very satisfied customer.

Before we go any further, I'll outline that one of the first things that I did was to grind the fixed firing pin off the bolt, that way there is no question of constructive possession. The bolt is soon to be modified to semi auto anyway, but I don't want to raise any eyebrows here. Everything I build is above board, and I go out of my way to ensure I meet the letter of the law. Here is a pic of the bolt with no firing pin, and a couple shots of the torched receiver chunks.

What we have here is a welding jig I machined, it's a block of 6061 aluminum stock clearanced for the feed ramp, ejector, and other items inside the Uzi receiver, and has copper plate sides. This allows me to weld the receiver together with no warpage, and does not allow the welds to burn through the sheetmetal. This jig fits very, very tightly inside the receiver, and any adjustment must be made with a rubber hammer.

Here I am aligning the front trunnion section with the next section of metal on the jig, and using a flat piece of aluminum to set the jig depth. The slag has been ground off the sheetmetal, as well as some of the paint on the edges to be welded.

 Now, I have the front half of the Uzi rewelded, or at least part of it is rewelded. I need to make some small filler panels to cover the larger gaps made by the cutting torch. I also have the rear two sections rewelded, and all I lack is the middle section of receiver, which I will cover at a later date. Before I can go any further in welding up the entire receiver, a blocking bar MUST be welded in the receiver to prevent insertion of an original, unmodified, full auto bolt. The blocking bar shows your intent to only use the firearm as a semiauto, and guarantees that a bolt with a fixed firing pin cannot function in the receiver. Once the blocking bar is welded in, the receiver pieces can be welded into a whole receiver.

The overall dimensions of the Uzi receiver will be set by a series of drawings, as well as using the parts that come with the kit to set spacing. The topcover will set the overall length, while the folding stock was used to set the spacing on the rear two pieces and the barrel was used to set the front two sections.

 Since I was tired of welding on the receiver, I moved over to the mill, and drilled out the bolt for a floating firing pin, and also started drilling out the area where a blocking bar will be in the receiver.
Below are two bolts that are in the process of semiauto conversion. A number of welding and milling operations are done to the bolts before they are semiauto compatible, and these still have a way to go.

If the Uzi is something that interests you, go check out and read up on the Uzi and its colorful history. If building one is on your bucket list, you should head over to the weapons guild and look into all the tutorials on how to build one of your own.
I'll have more on this build before too long.


  1. Very nice. Will this be a Carbine, Pistol or will you SBR it?

    1. DERP just re-read the title :)

    2. No worries, I have mornings like that too.
      The long term plans are to make it integrally suppressed, so it has a reason for having a long barrel. Until then, I will weld a barrel extension on, and put a fake can over the barrel extension.

      I have a bunch of different handguns that are primarily for carry purposes, but pistols based on a rifle aren't my thing. I'd rather SBR them, or just build them into full carbines. They're heavy, hard for me to aim, and serve very little purpose other than being range toys (not that I have anything against range toys).

  2. I envy you sir. Very nice project.

    1. Thank you for your kind words, let's just hope it turns out as nice as I'm hoping.

  3. Very nice. Much knowledge and skill.

    1. Thank you for your compliments.
      Come back by and check in with us.

  4. great post looking fwd to updates

    1. Thank you, I should have some updates in a few days.

  5. Awesome work sire. Any chance you could provide the measurements of the jig you build or even better yet, sell a jig? I'm interested.

  6. The jig is just two thin copper plates with an aluminum block between them. The length is arbitrary, as you will use your top cover to set the overall length of the receiver.
    I could sell a jig, yes.