Author Topic: Fitting the national match barrel bushing/new barrel  (Read 1518 times)

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Offline 1911crazy

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Fitting the national match barrel bushing/new barrel
« on: November 27, 2010, 05:33:54 AM »
Here's a pic on how i fitted the national match barrel bushing to my norinco.

First you need to fit the new national match barrel bushing to the slide.

Then get the barrel to sit into full battery with no barrel spring.

Then i fit the bushing so the barrel can hinge from full battery lock up into loading the next round.

The loc up is offset allowing the barrel to hinge up and down again with no barrel spring in either position.
Yet it has 100% lock up with no movement when its in full battery,

Sorry for the poor drawing the "C" is more of a short "U" shape that wrapps about 50% around the barrel so it holds it firmly when its in full battery. With my norc shooting cloverleafs it proves it works.

Offline odoh

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Re: Fitting the national match barrel bushing/new barrel
« Reply #1 on: November 27, 2010, 11:00:23 AM »
Interesting concept that I  hadn't considered. . . . I like it. Could you elaborate on the 'barrel spring'? Are we talking spring type spring or mechanical stress/tension on the barrel?

How about a few comments on fitting the bushing to the slide?

Can tell you are big on the 1911  ;)


Offline 1911crazy

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Re: Fitting the national match barrel bushing/new barrel
« Reply #2 on: November 28, 2010, 06:13:36 AM »
I fitted the national match barrel bushing to the slide first.  I buffed the barrel bore in the slide till the national match barrel bushing was loose till the last 1/4 turn it became a little snug so the barrel bushing wrench is needed for that last 1/4 turn.  Now with the barrel in the barrel bushing installed into the slide the barrel can be on an angle so the bushing needs to be trimmed until the barrel is in full barrety lock up with no barrel springing.  The barrel can bend like springing when the bushing isn't fitting correctly.  Once its fitted into full battery with no springing by removing a little material on the lower front of the barrel bushing and the upper rear part of the barrel bushing.  Remember to go slow and not to revove too much material.  These two front lower and upper rear sections are also used to clamp and hold the barrel firmly when its in full battery.  Again go slow at fitting the barrel for the full battery lock up.  I had no problem with the new barrel going into the lugs on the slide it engaged them perfectly.

The next part is fitting the barrel to the national match barrel bushing so the barrel can hinge down so it can load the next round.  Again with no stress or bending of the barrel when it goes into the lower position. My print shows this area on the upper front and the lower rear sections that need to be ramped for clearance so the barrel can actually tilt when it moves from full battery into the load condition.  As my print shows the rear upper section is like an open "C" facing down while the front lower section is the other open "C" facing up.  This offset "C" 's actually clamp the barrel when its in full battery giving us the much better accuracy that were looking for.
My $59 new 45acp barrel from sportsmans guide and my $12 new IAI national match barrel bushing from CDNN investments were fitted this way into my well used norinco 1911a1.  It now shoots one clover leaf per mag no matter who shoots it at 25yds.  I'm not worried about the group size yet, i'm still surprised on how it shoots one clover leaf per mag.  My slide is still very loose from it being well used.  I may try to do some slide tightening work next.  I already have the swage tools to do this operation.  Then by tightening the slide just a little i wonder how much better it will group. I don't want to tighten the slide to frame rail fit too much so i lose the reliability too. I also need to add better sites on it too. I have the orginal 1911 low sites on it.

I never did this kind of pistol work before. Being a class A machine builder/erector and an engineering lead tech for so many years i figured it would be another challange and easy to learn how to do it.  I did pick up the armorers video and the book on 1911's so i had some insite on what i needed to do.  I just wanted to get more familiar with the 1911 parts too.
I figured why not rework my own 1911.

Here's a better copy/drawing on the barrel bushing work.


Offline 1911crazy

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Re: Fitting the national match barrel bushing/new barrel
« Reply #3 on: November 28, 2010, 06:33:09 AM »
Mikey;  Do you understand what i'm trying to say?   I just want to make sure that i say everything so its understandable.  I'm trying to put on paper whats in my mind so its clear to understand it.  Its hard for me to do this sometimes.  I'm trying to walk everyone thru it about what i did. Please ask questions too i'll be glad to help you walk thru this operation.

Barrel springing;  Is when we push the barrel into the lugs when we have the slide off the gun and the barrel & barrel bushing still assembled.  If we push it into the lugs and it springs back the locking part of the barrel bushing still needs to be tilted a tad till the barrel locks in the lugs when we push it and it stays there on its own with no springing back out. After we fit the new barrel bushing to the slide we need to fit the barrel to it so its on the exact same center line of the bore when its in full battery.  Nothing is a given that its square nor will it fit right when we assemble it for the very first time.  We just can't remove and replace the parts its not going to happen and be perfect right away.  We will become gunsmiths by our own fire in time. I want the hands on to learn all i can about the 1911's and other guns too.

Remember the 1/4" area is completelty round too.  I showed the angles so you can understand were to angle the bushing so the barrel can tilt and fully go to the full battery position.