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anthonywwalker
01-01-2013, 8:04 PM
After shearing off a foot and a half piece of allthread and embedding it into my garage wall, I broke down and bought a press (harbor freight 20 ton, regular $229, on sale for $169 and I dropped a 25% off coupon on em). I got my barrel pressed in, using the scoring marks on the trunnion from the original barrel as a starting reference. I have a set of go/no go headspace gauges but the bolt closes and locks up on both. This doesn't seem right.

Also, I was under the impression the no-go gauge was supposed to be longer, but my go gauge is actually .2 mm longer than the no-go. Most likely I'm just doing something wrong and don't know how to properly use my tools. Any advice?

BR7.62
01-01-2013, 8:08 PM
that is wierd about your gauges measuring like that. might just be the cone at the front that doesnt touch the chamber walls showing that measurement?
sounds like it needs pressed in further.
i like to make it quite tight on the go gauge.
this ussually makes a nice fit on most of my ammo.
can you lock them both and wiggle the bolt front to back at all?

anthonywwalker
01-01-2013, 8:12 PM
Yeah, I still have a bit of wiggle with them both locked down. As far as the gauge measurements, I measured them with digital calipers before I started checking the headspace.

BR7.62
01-01-2013, 8:16 PM
keep pressing! just go a touch then check until you get it.
maybe google search for videos. would give you a better idea what youre looking for.

FTC
01-01-2013, 8:51 PM
Is the barrel original? How's the pin hole look? You cant measure the gauges with a caliper, they measure off a point mid taper on the shoulder

anthonywwalker
01-01-2013, 8:54 PM
Its a virgin barrel that came with my Romy kit. After watching a few vids and such, it appears as though I need to press it in a bit further.

nicoroshi
01-01-2013, 9:13 PM
the distance of the gauges that is important is from the bolt face to the datum line NOT the front of the gauge.
http://www.surplusrifle.com/shooting/headspace/graphics/l/rimless.jpg
Also there are different guages available, and if doing an AK you need to use the Russian spec ones not US spec.
The bolt should close snug on a GO guage, and should not close on a No-Go gauge.
Example>>>
http://firingsquad.us/wp-forum/gallery/4-020113001159.jpeg

If it closes on both the go, and no-go you need to press t he barrel in further until it can close snug on a go, and not close on a no-go.

anthonywwalker
01-01-2013, 9:17 PM
Thanks Nico, this helps a ton.

anthonywwalker
01-01-2013, 9:17 PM
Thanks Nico, this helps a ton.

nicoroshi
01-01-2013, 9:24 PM
Gotta love visual aides :)

Head space is not something to monkey around with, and the tolerance is very small between a go, and no-go gauge (~.005").
Check multiple times.
Set, check
Drill/ Ream, check again
Set Pin, check again
When pressing barrel back in after trunnion is in receiver, check again
Then for giggles, check one more time
40K lb/in2 is not something you wanna be wrong on.

Anti-Hero
01-01-2013, 9:58 PM
Could it be that the chamber was cut too deep on the virgin barrel? I've read a lot of disconcerting reports of US made barrels being way out of spec. on some AK builds.

anthonywwalker
01-02-2013, 4:16 AM
I was gonna buy something with that harbor freight coupon, but I go to order and everything is marked up 25%, the 20 ton press is now $250. I dont see any items that are discounted in red like they usually are :mad:


I really wanted to use it for a compressor, but the coupon stated that it couldn't, even tried to slip it past the cashier, but she was onto my tricks and shot it down :)

anthonywwalker
01-02-2013, 5:57 AM
So I pressed my barrel in a bit more this morning before work. Pressed, checked, pressed, checked. Was still off by just a hair so I pressed it one more time and it popped and jumped about a mm too far and now it won't close on either gauge. GRRRR I had to seriously fight off the urge to press it back out a hair but I would've been late for work. Damn shame a man has to work to afford his hobbies, leaving him precious little time for aforementioned hobbies. Thanks again for the clarification Nico, I knew exactly what I was looking at and looking for after your explanation and pics.

nicoroshi
01-02-2013, 8:56 AM
You're welcome.
Little trick for you.
When applying pressure to press in dont go all the way until it pops too far.
Apply some pressure then hit the ram of the press with a mallet.
It will wiggle it just enough to move just a little rather than building up a lot of pressure and jumping a lot.

klewan
01-02-2013, 11:35 AM
Could it be that the chamber was cut too deep on the virgin barrel? I've read a lot of disconcerting reports of US made barrels being way out of spec. on some AK builds.

That was the case probably 2 or 3 years ago. From what I read, S&W used a .223 barrel diameter for their 5.45x39 upper instead of the .214. Other barrel makers copied S&W, so theirs weren't right either. Another barrel maker shipped .223 barrels instead of the .214, lots of key holing problems. All of these were 5.45, never really saw 7.62x39 being butchered to this extent.

Charlie50
01-02-2013, 11:42 AM
You're welcome.
Little trick for you.
When applying pressure to press in dont go all the way until it pops too far.
Apply some pressure then hit the ram of the press with a mallet.
It will wiggle it just enough to move just a little rather than building up a lot of pressure and jumping a lot.

This ^^^ You da man! More expensive solution, don't ask how I know:rolleyes:... is a bigger press, tends not to jump.

BR7.62
01-02-2013, 12:58 PM
its the tolerance that makes it jump.
to tight it will pop and jump, to loose it will slide in to easy.
bigger press can cause trouble if you arent carefull.

nicoroshi
01-02-2013, 3:46 PM
its the tolerance that makes it jump.
to tight it will pop and jump, to loose it will slide in to easy.
bigger press can cause trouble if you arent carefull.

Agree.
I have a building friend who thought it would be good to buy a 20 ton press instead of a 12 ton. There is a bent barrel somewhere in his shop now.

0nTarg3t
01-02-2013, 9:02 PM
anyone have an idea where i can get a 5.45 x 39 Headspace Gauge no go? i cant seem to find one anywhere

nicoroshi
01-03-2013, 4:12 AM
anyone have an idea where i can get a 5.45 x 39 Headspace Gauge no go? i cant seem to find one anywhere

I picked mine up from AKbuilder.

kcstott
01-03-2013, 5:21 AM
Brownell's has them.

0nTarg3t
01-03-2013, 7:12 PM
yea akbuilder is sold out,but i did get one from Brownell's :balloon:

thanks for the tip.

Ryan in SD
01-04-2013, 2:35 AM
So I pressed my barrel in a bit more this morning before work. Pressed, checked, pressed, checked. Was still off by just a hair so I pressed it one more time and it popped and jumped about a mm too far and now it won't close on either gauge. GRRRR I had to seriously fight off the urge to press it back out a hair but I would've been late for work. Damn shame a man has to work to afford his hobbies, leaving him precious little time for aforementioned hobbies. Thanks again for the clarification Nico, I knew exactly what I was looking at and looking for after your explanation and pics.

Haha I think everyone here knows that feeling. You will get it. Hopefully you have decent tooling to monkey around with. Makes life easier.

Bamfak47
01-06-2013, 3:16 PM
I have heard that you should use a field gauge not a US no go especially if you are going to shoot foreign ammo as if you use the nogo gauge a lot of non US ammo jams and if it is lacquered then you have no room for the build up when your barrel gets hot and you get jams!!

As far as I know the AK is so successful because it was designed and built to have a large margin of looseness. Like up to a 1/4". Some of these guns are built with just hammers and really rough tools but the guns keep firing! If you guys have other data please fill me in!! As I have a friend that has built over 1500 aks and just uses a field gauge and does not recommend using U.S. no goes etc.

Ryan in SD
01-06-2013, 7:23 PM
Like up to a 1/4".

Im calling BS

nicoroshi
01-06-2013, 7:29 PM
Im calling BS

I second that.

Difference between the go, and no-go gauges is roughly .005"
I also call BS on your friend having built 1500 AKs.
I build or help people build (and have done so for more than 3 years) all the time and am just over 200 that I have had a hand in building or tutoring.

Clearly you are unfamiliar with firearm construction.

Note to self: Stay very FAR away from anything Bamfak47 or his friend has built when they try to test fire it.

chiz
01-06-2013, 8:43 PM
As far as I know the AK is so successful because it was designed and built to have a large margin of looseness. Like up to a 1/4". Some of these guns are built with just hammers and really rough tools but the guns keep firing! If you guys have other data please fill me in!! As I have a friend that has built over 1500 aks and just uses a field gauge and does not recommend using U.S. no goes etc.

1500? Thats 1 a day for 5 years. I would be sick of building AKs. I have had almost 200 leave my garage and that was a ton of work. I know some who owns and has built way more than me and has been doing alot longer and is not even that close. Maybe he is the guy that keeps bending receivers but never finishes a gun.

Bamfak47
01-07-2013, 7:17 PM
Ya it was not 1500 by himself :) sorry, but he has been building them for 25 years & has his own ak company so it was not him personally that built them. Once again sorry for the wrong data!

Well happy builds!! He just gut 450 barrels in so its one big time build party!!!

nicoroshi
01-07-2013, 7:23 PM
Ya it was not 1500 by himself :) sorry, but he has been building them for 25 years & has his own ak company so it was not him personally that built them. Once again sorry for the wrong data!

Well happy builds!! He just gut 450 barrels in so its one big time build party!!!

Company name?
Please.
Inquiring minds would like to know.