Headspacing an AK with Gauges

[HB of CJ 1,263]

Rotating the head space gage about 10 times is also a good data base for determining if one needs to remove the extractor and perhaps the ejector if the bolt head has one.  If when the rotation "feels" different when checking head space, then the extractor must be removed.  Possibly also the ejector.  Maybe not.  Just a little bit more knowledge and experience.  Respectfully.  Also I am less pissed today.  Yikes!   Remember ... Vodka is your friend!

 

Edited by HB;  I really need to learn to proof read.  Shit.  What I meant to say is that if when checking the head space AFTER slightly rotating the gage one tenth turn and the feel is different then the extractor and possible ejector will need to be removed from the bolt head.  Also looks at the lugs.  Also again inspect the chamber.  If the extractor has already been removed and the feel is different then perhaps the lugs or chamber may have a concern.  Repeatable techniques.   As stated before it was confusing.  But then again I confuse easily these days.  Actually all the time.   Shit.

Edited December 16, 2015 by HB of CJ

[6500rpm 670]

^^^See, one old dog tought another old dog a new trick. I was off today and took an old buddy out for lunch and a few beers-I'm way less pissed right now and won't be working on firearms for a bit!

[netpackrat 566]

Always check the load share of the locking lugs with dyechem or a blue sharpie BEFORE head spacing! ( new , old no difference, check luges BEFORE taking gauges out)

I believe you should JUST 'feel' the gauge on a go gauge. You should not FORCE a no-go gauge, one oiled finger should not get you more than 75% rotation.

On a precision build 25% rotation for the no-go. For cheching a working gun, as long the no-go does not rotate 100% it is good to go.

 

Go/no-go gauges are only designed for setting headspace on a new rifle.  If the no-go gauge will chamber in a working rifle that originally wouldn't chamber a no-go when it was built, that doesn't necessarily mean that headspace is bad, that just means it is showing some wear.  There is also a "field" gauge that is used to check for headspace that is beyond the service limit for a used rifle.  If the field gauge will chamber, the rifle should not be considered safe to fire.

[netpackrat 566]

Netpackrat, I do have one of the 54r No Go gauges you spoke about that I used on a couple Mosin's before buying. I'm starting to play with a PSL build and one of the members over at the Files is doing the chamber end cuts for me on a donor Finnish Mosin barrel. I'm still trying to wrap my head around the function of the "safety ring" the PSL incorporates at the chamber mouth.

 

The PSL is a kludge, and if you spend much time working on them, you will develop a really fine hatred of Romanians.  Once I get mine running right, I am probably going to sell it.  I just haven't had time to mess with it lately.  I think the goofy ring at the chamber mouth is there to fuck with home gunsmiths.  On one of the kits we built from, that ring was damaged slightly by the orangutans who originally de-milled the rifles.  The idiots even ground off the bayonet lugs and welded the flash hiders (on demilled parts kits!) so we had to get those parts from Apex to keep them looking right.

 

The Romanian made receivers we bought were total garbage...  One wasn't too bad, the other (mine) had some bad riveting, upper receiver rails not machined properly...  I still need to remove some metal because there is too much drag, which causes my rifle to be a straight pull bolt action.  The factory side rails were also not machined to final dimension.  NDS wasn't making their receivers yet when we bought our parts, otherwise a lot of the problems could have been avoided.

 

Magazines are serial numbered to the original rifles and do not necessarily interchange.  My brother and I bought a total of 12, and were able to sort them into 6 that work in his, and 6 that work in mine.  If you thought that Saigas had a lot of magwell variation, the PSL makes them look like a wonder of precision manufacture.

Edited December 15, 2015 by Netpackrat

[SGL 530]

Go/no-go gauges are only designed for setting headspace on a new rifle.  If the no-go gauge will chamber in a working rifle that originally wouldn't chamber a no-go when it was built, that doesn't necessarily mean that headspace is bad, that just means it is showing some wear.  There is also a "field" gauge that is used to check for headspace that is beyond the service limit for a used rifle.  If the field gauge will chamber, the rifle should not be considered safe to fire.

 

 

Thanks for sharing this.  I always wondered about the purpose of a field gauge.

[mancat 2,368]

My AES-10B's receiver's right side lower rail is wavy, looks like a wet noodle. Not sure what the hell they did when bending it, and it should've been tossed out, but someone went ahead and welded it in. However the rifle has never failed at all, and shows no signs of abnormal wear to the rail or the carrier - just a couple rub marks on some of the high spots of the "waves" on the rail.

 

Shows how tolerant the design is of manufacturing fuck ups.

[Sim_Player 1,939]

My AES-10B's receiver's right side lower rail is wavy, looks like a wet noodle. Not sure what the hell they did when bending it, and it should've been tossed out, but someone went ahead and welded it in. However the rifle has never failed at all, and shows no signs of abnormal wear to the rail or the carrier - just a couple rub marks on some of the high spots of the "waves" on the rail.

 

Shows how tolerant the design is of manufacturing fuck ups.

When my kit's lower rails were welded, one of them were "off". I fixed it with ViseGrips and a file. The bolt rides very smooth now.

 

It's simple in design. That's why we love it!

 

Mention ViseGrips around AR15 building guys.

Edited December 16, 2015 by Sim_Player

[G O B 3,516]

A FIELD gauge is mainly a military expediency to keep up the number of guns in service. If you are a civilian it is best to start saving for a repair when the no-go gets sloppy, the field is when you should take the gun out of 'service', unless it is just a lookey loo, or very lightly used.

Paper punching with steel cased ammo is a better use of a worn gun, as any accuracy is going away, and brass will be stretched to where reloads need excessive cold working, and will get brittle and split. Some say 'just reload the stretched ammo for that gun only', I say that is just foolish stop-gap that puts BAD ammo into any other gun you may have in that calliber!