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
polish underfolder head space
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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...
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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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.
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?
"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.
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.
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
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
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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651 Posts
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.
" 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
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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2,235 Posts
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
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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