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.

Tuesday, July 2, 2013

Sunday, H&K Sunday

I had a reader contact me last week about the conversion of Suomi drums to other 9mm firearms. I've gotten a degree of success in getting the drums to run in other weapons, but the Hi Point is still elusive. Out of 70-ish rounds, I still get 1-3 failures to feed. In an Uzi, a MAC, or an MP5, where there is a lot more room to work with in the mag, I have little to no trouble getting a reasonable feed. This reader wanted to know everything I knew about converting one for use with an Uzi, specifically a transferable machinegun. We did some story swapping and talking, and as it turned out, he was able to come visit the Redneck palace this last weekend.
Little did I know that he was bringing a ton of guns and ammunition, most of which were either NFA registered receivers or registered sears. I got to fire one of almost everything that H&K has ever made, including, but not limited to:
HK 11, 51,53,mp5, mp5k, mp5k reverse stretch, 23/21e, and two different 91's

There was also an AR15 with a DIAS , as well as a DLO Uzi and a Mac10 in .45acp, with a suppressed Lage upper. Aside from my carry piece, there was one other semi auto there, a Saiga 12. A Serbu Super Shorty made an appearance as well.
(Side note: if anyone ever hands you a H&K51 with a 50 round drum under it and an autosear, make sure you have a mouthguard in place, and earplugs under your outer hearing protection. A little suntan lotion wouldn't hurt, either. Jeebus, that was intense.)

The gentleman in question drove all the way from another state just to pick my brain and let me run some ammo through his MGs. I am still in awe of his immense generosity.

We spent Saturday working on a drum to see if we could get one of my designs to work in his gun, and we did indeed get one to cycle a full drum by hand in his gun simply by cycling the bolt (70 times!), so we knew we had something worth taking to the range and trying out.
At the range, it fed fine in semi auto, but the first time it was tried in FA, it had a couple of stoppages. These were due to friction, as we would later find out. I did some tinkering with the drum, loaded it all the way full, then did a complete drum dump (~70 rounds) in semi auto with no problems. Next, I tried it in FA, and had one stovepipe and two failures to feed, before I got about 65 rounds out of it in a row with no problem whatsoever. It ran and ran and ran. Even in full auto fire, I didn't think it was ever going to end.
Since it runs fine in semi, I believe friction kept it from keeping up with full auto feed rate. The owner of the Uzi took the drum home and is going to work on the friction issue, and maybe he'll come out with something worth making more of. I think he will, he's just got to get the bugs out.

 Anyway, enough talk. Let's look at machineguns, shall we?

 Here's the owner shooting his MP5k with a Vector drum under it
Me and a buddy shooting the MP5k

The AR15 with lightning link

The MP5K. I don't know the difference between this K and the last one I shot, except that the cyclic rate on this one is almost insane.

I believe this was a HK53

My all-time favorite of the day, the 51. MUST HAS NAO!

More of the 51

My friend shooting the Mac10 with Lage upper and can.

Shooting the MM11. This is just wrong. You don't put a gun like this in my hands and expect to take it back from me.

Shooting the 23e. THIS. IS. JUST. NOT. FAIR.

Shooting the same 23e, but with the bolt, feed tray, and barrel in for a 21. (In other words, going from .308 to 5.56 in a few seconds.)

I now know that the NFA34 was not drafted by a bunch of men wanting to reduce crime, but by a number of married women who were tired of their husbands bringing home new machineguns every day and sitting out in the back pasture shooting and ignoring the wives. There's just no way a woman can compete with a large machinegun collection until you either run out of ammo or something breaks.

A TON of gratitude goes out to my new-found-out-of-town friends Scott H. and Houston H.
I'm glad y'all tried to get in touch with me, and I hope we can/have come up with something functional with the drums for your Uzi.