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Discussion Starter #1
On one of my builds, a polish underfolder, the barrel came removed from the trunion in the kit like most that I have seen. When I pressed it in with my 12 ton press it went in easy and the holes for the pin lined up perfect. Beginners luck, I thought. I don't have any reference as to where the barrel was in the trunion originally since it was apart when I recieved it but because the holes lined up perfectly I thought I was good to go. That's what i get for thinking! Headspace way too excessive. What's the deal. The numbers all match on the kit so I don't understand this. Any idea's. Or should I say solution's. ak'sr4me
 

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Sometimes a few 1/1000ths is tough to see. Maybe, everthing wasnt lined up perfectly. Bup it in till the headspace is right and everthing still may lool lined up.
 

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Bump it in, and a few shots later, it will be bumped OUT. If you have excesive headspace on a drilled barrel, you will need help. Your options are:

weld the notch in the original, turn on a lathe, re-drill
oversized pin
new undrilled barrel

Number 3 is better for a long term shooter, number 1 or 2 if the kit is rare. 2 only works if the headspace isn't that bad. Were it me, I would seek out the help of Chris at AK103.com. He was able to fix one of Informer's wonders that had the same issue...
 

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I am just wondering, how did you check head space??
 

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This sounds like it will get expensive! I don't know if it is good or not, but I haven't heard of many people at all having problems with headspacing. This makes me wonder more about the headspace on my first build and whether I should by a set of no-go gauges before I test fire it. I was thinking about tying it to a tree instead.
 

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Discussion Starter #6
I haven't ever had any problem with headspace before, but I always marked the position of the barrel in the trunion before I removed them. The polish one comes unassembled. I made a crude set of go no go guages with 2 rounds that I emptied the powder out of and pressed the bullet back in. One I left alone for the go guage and the other I took a .005 feeler gauge, cut it to the size of the casing head and super glued it to the shell case. On all my builds and also my SAR 1 the no go won't allow the bolt carrier to close. On the polish build, even with 2 pieces of masking tape placed on the no go guage the bolt still locks up. I am going to press the pin out today and bump the barrel in until it headspaces and see how far off the holes are. I hope I can get get away with just putting an oversize pin in. What is the max diameter you can go for oversize? Can I make a pin or do I have to buy one?
 

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"I made a crude set of go no go guages with 2 rounds that I emptied the powder out of and pressed the bullet back in"

No - you need some REAL gauges. If this is what you are basing "failing a no-go" on, you may not actually have a problem at all...

You see, you can't make a no-go from a shell unless you have found a way to stretch the shell. BULLET length/distance means nothing as far as headspace is concerned. I may be wrong, but it sort of sounds like you are varying bullet depth?

What do you get with a LIVE round (firing pin removed for this test!) and Tape? If the bolt locks with about 2-3 pieces, you have an issue. Now - thats not a lot - about 6/1000's. You can cure this with a pin that has 2X (12/1000's) greater diameter, as you are working on expanding the radius. But you MUST hold that barrel fixed durring the drill process - you want to leave the "rear" undrilled, and expand the barrel notch FORWARD while insuring your oversized pin hits the sholder in the REAR.
 

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Discussion Starter #9
I ordered the go and no go gauges yesterday. I feel kind of foolish because I pressed the barrel pin out today and bumped it forward ever so slightly and a live round would not even let the bolt lock up. I put it back the same way it was and said f it and tested it with a full 30 round clip. It works just fine. someone on this board told me that all you had to do was put a couple pieces of tape on the end of the shell and it should not lock up. That is what I have been basing my headspace on. 2 pieces of masking tape measures about .005 so that is why I did what I did with the shell casing. Hell, I am a newbee. Give me a break. ak'sr4me Why do you have to remove the firing pin and extracter to check headspace?
 

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I know this is not the best method but I got the idea from another guy and did it myself. I bought a set of feeler guages for 99 cent I carefully cut a disk from each guage. the disk is a bit smaller than the back of the case. I carefully pull the head out of a new round, put a bad of grease on the primer and stich the feeler disk to the case. I usualy start with ten thousandths and if the bolt will not close I then go to nine, and if the bolt will not close I go to eight. the first guage disk that the bolt will close on is the head space for that case. The first time I did this I did it with a bunch of differant brands of ammo and they all were basicaly the same.
Yes I realize this is not the same as a go nogo but I am very happy with it and have had good results.. end result is I know what the space is and I decide if I am going to run it or not. if your guage said it is too tight it would not tell you how much too tight. maby one thousandth will ware in in a few hundred rounds on a new kit.
I know I know ,.,, BLA BLA BLA but it works for me. and yes I allways use the old behind the tree trick for the first few, no matter what head space I get..LOL
 

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Discussion Starter #12
What is the difference in thousands of the go and the no go gauge??? What is exceptable headspace. Example .003 to .005. I did the behind the tree thing last night and I emptied a 30 rounder with no problem, so I think I am alright with the headspace, but I will wait till my headspace gauges come and check it out before I put it into action.
 

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ak'sr4me said:
I am going to press the pin out today and bump the barrel in until it headspaces and see how far off the holes are. I hope I can get get away with just putting an oversize pin in. What is the max diameter you can go for oversize? Can I make a pin or do I have to buy one?
I have made pins from air hardening drill rod. I was installing an oversized pin that i purchased from Global. I drilled the hole too big, so I then made a pin from 7/32 drill rod.
It seems fine.
 

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Discussion Starter #14
I got the go no go gauges today and checked the headspaing with the firing pin removed . It is properly headspaced and good to go. Thanks for all your comments and help. ak'sr4me
 

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using a cartridge to make a go/no go gauge only sets you up to the lands and grooves for a specific bullet ogive. this in no way tells you anything about bolt face to shoulder dimensions, which is the critical part. Go to midway.com and get yourself a good headspace gauge. Not real expensive, and will tell the truth about any headspace issues.
 

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" got the go no go gauges today and checked the headspaing with the firing pin removed . It is properly headspaced and good to go."

THERE you go... cheap, given the peace of mind you now have :) Those gauges will let you sleep at night for many AK's to come :)
 

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There are 2 standards on gauges
the American and the Euro (I know that are called something else)
There is a difference in dimensions.
I built a romainion. It was my first, and last screw together.
Once I had it together I put a live round in it and it closed all the way just like it should.
I carried it to my local smith and bud, had him check it with his gauges.
Both the GO and the NO-GO would not allow the bolt to close. But It would close on a live round. I carried i to the range with my bud Z_recto. Blasted 75 rounds out of it with no problems.

I can't remember the exact measurements, but using EURO guages the difference between go and no-go is HUGE
 
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