Uzi barrel will not fit into the trunion.

[Blitzkrieg]

I recently bought a McKay Uzi receiver, Mckay complete semi auto bolt with buffer, sa firing pin, and a 16 inch barrel from Mckay. The barrel stops about a half inch shy of fitting into the trunion. It is the thick collar in the middle of the barrel which keeps the barrel from moving down into the proper position. What is the normal measurement for the thick ring in the center of the barrel? I just paid about a $145 for a 16 barrel from Mckay. Should I purchase another barrel from Green Mountain and see if their barrel will fit. I do not want to modify the inside diameter of my trunion if it is the barrel that is out of spec.

Second question. Any recommendations on someone that can weld my selector in the safe and semi auto position, ream the trunion if necessary to allow barrel to fit, remove front and rear sights on the original demilled receiver and put them onto the new McKay receiver, and parkerize or blue the receiver. I would like to keep the barrel, bolt, cover in the original finish.

I also have a full auto bolt, stainless steel barrel, firing pin, and buffer that I would like to sell. All the parts are in very good to excellent condition.

 

[Wolfhollow]

You probably have an SMG barrel. Band will measure .748 SMG Trunion .750. SA barrel .708 SA Trunion .710

 

[Blitzkrieg]

I tried both the SMG barrel and Semi Automatic barrel and neither barrel fits into the trunion.

 

[chipster]

Get a hold of McKay and work with them to have the issue with the barrel/trunion fixed. There is no reason why you should be on the hook for problems with new parts like this.
http://www.mckay-ent.com/contacts

Maurice McKay has been good about getting back to me on any concerns. I'm sure you'll want to e-mail a picture of where things are blocked - their direct e-mail behind the form is simply info@mckay-ent.com

Regarding welding the selector stop - all you need to do is find a gun friendly welder and unless you live in liberal-ville (Seattle in my case) that should be easy. Take the dimensions between the front inside of the grip stick and where the selector rests at Semi Auto (which McKay basically lists in their build-up docs shipped with the receiver) and go find a washer @ your local hardware store (Ace Hardware is my fave for this since they allow you to purchase in 1-2qty and not an entire package). The trick with the washer of the proper dimension is once centered in the grip stick, the selector(when being pushed towards FA) just impacts the rear of it and transfers the force to the front of the grip stick - the washer basically becomes the 'spec' for the block itself. The welder just needs to weld the center (or sides) of the washer to the inside of the grip stick. Presuming you get the right dimension washer (and obviously you test this with the stripped grip stick + selector before welding) the only way to screw this up is if the welder goes to town and lays down a ton of weld material on top. If there is too much weld material the sear won't be drawn down far enough to allow the striker to be released. Resolution if that happens is just to grab a dremmel and grind down excess weld material. this is what a finished washer block looks like and since this one was used a bit, you can see a little outline of the selector as it sits in semi position right behind the washer.

 

[chipster]

double-post

 

[Wolfhollow]

I tried both the SMG barrel and Semi Automatic barrel and neither barrel fits into the trunion.

Measure the barrel band and measure the inside diameter of the trunion.

Post measurements.

You very likely have two SMG barrels.

On the Semi auto barrel the front and rear band should be the exact same diameter.

If you can't find a Welder I will do it for you. I charge $55 that includes return shipping.

 

[RoverDave]

Also check to make sure it's not the chamber end of the barrel that won't fit through the barrel restrictor ring.

 

[Blitzkrieg]

I called McKay Enterprises and it is really nice to be able to talk to a customer service representative. I told him that my barrel that I purchased from McKay Enterprise did not fit into the trunion of the quasi finished gun kit that I also purchased from McKay Enterprise. He tried another barrel and he said it fit into the trunion of a semi automatic Uzi he had on hand. Maurice from McKay Enterprise said if I sent him the barrel he could get a hand file and open the diameter of my trunion. I appreciate his willingness to help but I am somewhat apprehension to have someone take a hand file and open up the diameter of the trunion. I am thinking about having it reamed out using CNC machinery. My gunsmith said he would help and said he was familiar with the Uzi. So I brought the semi auto bolt to him and for 15 minutes he kept trying to put different pieces of the semi auto bolt together with no success. Then he asked me if I brought a shematic to put the semi auto bolt kit together. He then used one of my IMI magazines to whack a pivet pin out of my Uzi receiver with the additional help of his pocket knife. Then he said, I could paint this up real nice with some duracoat for $200. I really just want to get this Uzi running before I start painting or refinishing it. I asked my gunsmith I thought you told me you were really familiar with the Uzi and worked on many of them. He said he was very familiar with the Uzi but only the full auto Uzi. He said he has never seen a semi auto Uzi bolt before.

 

[Wolfhollow]

I called McKay Enterprises and it is really nice to be able to talk to a customer service representative. I told him that my barrel that I purchased from McKay Enterprise did not fit into the trunion of the quasi finished gun kit that I also purchased from McKay Enterprise. He tried another barrel and he said it fit into the trunion of a semi automatic Uzi he had on hand. Maurice from McKay Enterprise said if I sent him the barrel he could get a hand file and open the diameter of my trunion. I appreciate his willingness to help but I am somewhat apprehension to have someone take a hand file and open up the diameter of the trunion. I am thinking about having it reamed out using CNC machinery. My gunsmith said he would help and said he was familiar with the Uzi. So I brought the semi auto bolt to him and for 15 minutes he kept trying to put different pieces of the semi auto bolt together with no success. Then he asked me if I brought a shematic to put the semi auto bolt kit together. He then used one of my IMI magazines to whack a pivet pin out of my Uzi receiver with the additional help of his pocket knife. Then he said, I could paint this up real nice with some duracoat for $200. I really just want to get this Uzi running before I start painting or refinishing it. I asked my gunsmith I thought you told me you were really familiar with the Uzi and worked on many of them. He said he was very familiar with the Uzi but only the full auto Uzi. He said he has never seen a semi auto Uzi bolt before.

Like I said before before you do anything you need to take measurements with a micrometer. If you don't have a micrometer you need to buy one and learn to use it if you are going to be doing projects like this. The Mckay receivers do require fitting. This is not like putting together an AR15. You need to measure the Band on the barrel and you need to measure the inside diameter of the trunion. It may only be off by .001 or so. If that is the case a dowel and sand paper will do the job. Having this reamed out on a CNC is going to cost you a fortune. You don't setup a cnc and jig for something just to ream one trunion.

 

[RoverDave]

I called McKay Enterprises and it is really nice to be able to talk to a customer service representative. I told him that my barrel that I purchased from McKay Enterprise did not fit into the trunion of the quasi finished gun kit that I also purchased from McKay Enterprise. He tried another barrel and he said it fit into the trunion of a semi automatic Uzi he had on hand. Maurice from McKay Enterprise said if I sent him the barrel he could get a hand file and open the diameter of my trunion. I appreciate his willingness to help but I am somewhat apprehension to have someone take a hand file and open up the diameter of the trunion. I am thinking about having it reamed out using CNC machinery. My gunsmith said he would help and said he was familiar with the Uzi. So I brought the semi auto bolt to him and for 15 minutes he kept trying to put different pieces of the semi auto bolt together with no success. Then he asked me if I brought a shematic to put the semi auto bolt kit together. He then used one of my IMI magazines to whack a pivet pin out of my Uzi receiver with the additional help of his pocket knife. Then he said, I could paint this up real nice with some duracoat for $200. I really just want to get this Uzi running before I start painting or refinishing it. I asked my gunsmith I thought you told me you were really familiar with the Uzi and worked on many of them. He said he was very familiar with the Uzi but only the full auto Uzi. He said he has never seen a semi auto Uzi bolt before.

Wow, lots of problems indicated here. As Wolfhollow said, the first step is measuring the raised band on the barrel to see if that's in spec or not. So step 1 is to get your caliper out, measure the band, and post it here. If you don't have a caliper, ask your "gunsmith" to measure it. If he doesn't have a caliper, then you know he's not really a gunsmith. Once you post that number here, we can tell you how to proceed to step 2.

 

[sniperdoc]

Respectfully, your "gunsmith" story is scary!
No one should use a mag as a hammer or a pocket knife for, well, anything like what you describe.

 

[roscoeturner]

Anytime I hear the word "gunsmith" it makes me cringe. In my part of the world all an individual needs to call himself a gunsmith is a hammer, a vise and a business card.

 

[sniperdoc]

Anytime I hear the word "gunsmith" it makes me cringe. In my part of the world all an individual needs to call himself a gunsmith is a hammer, a vise and a business card.

Around here,most ppl only take their gun to a gunsmith after they have tried (&failed) to fix or modify a gun themselves.
You can imagine the extra work,parts,time,and money involved.

 

[roscoeturner]

Around here,most ppl only take their gun to a gunsmith after they have tried (&failed) to fix or modify a gun themselves.
You can imagine the extra work,parts,time,and money involved.

On those rare occasions I need to have a machine gun worked on I deal with people I know who only specialize in working on machine guns. Bubba the "gunsmith" I never allow to get close to any firearm I own.