ak help

[steve_dune]

I have an ak that does not fire all the time. The firing pin lets a dent in the primer on the round that doesn't go off. The ak has a round firing pin in it now I was wondering if the triangle shape one would fit? I think im going to replace the hammer spring and the firing pin. Is there anything else it could be? The firing pin is loose so its not sticking anywhere. Thanks

 

[Jim K]

First, how about the ammo? Can you check it in another gun? Also how about headspace? Was the gun bought as a whole or put together by someone?

Then check firing pin protrusion and the mainspring (hammer spring). I would not mess with the firing pin; it is supposed to be hemispherical on the end, and it is about the last thing I would think of giving trouble.

Jim

 

[steve_dune]

The ammo is fine in other guns. Is there anyway of checking the headspace without buying a go no-go gauge? The hammer spring seems pretty strong still. How far should the firing pin stick out? With out checking it with calipers or anything it looks like atleast 1/16".

 

[Malikovski]

You can improvise gauges with a cartridge and shims made out of feeler gauges, if you know the relative lengths of the real gauges. I had to do this for my 5.45 AK, as I couldn't find a source for gauges.

Feeler gauge is $5 at the auto parts store, cartridges you already have, so it's a lot cheaper than real gauges.

Just take the firing pin out of the bolt and be gentle so you don't end up hole in your workshop.

 

[steve_dune]

I removed the firing pin and the extractor. When I put a cartridge in the chamber and close the action on it, how much play should the bolt have? With the action closed on a round I can move the bolt at least 1/16" back and forth until it stops. I thought the bolt should be against the round which in return would make the bolt tight not allowing it to move.

The barrel looks like it used to be treaded then someone turned the treads off in a lathe to make it fit. Not sure how it should look. Since the barrel is a pressed fit with a pin holding it in an ak I would think that it should not have had threads on it ever.

 

[Malikovski]

Yikes.

There should be no play. At least none of my AKs have any play when the bolt is closed.

You need to fix headspace on that rifle. It sounds dangerously our of spec. Get a GO and NO GO gauge (I found mine on eBay for about $30) so you know what you're dealing with. Adjusting headspace on an AK is not hard, you just need a reamer the right size and some drill rod to make an oversize pin.

Sounds like someone converted a milled AK kit (with threaded barrel) to a stamped AK, but didn't do the headspace right. A sixteenth is huge in headspace terms. I would not fire that rifle until you determine exactly what is going on.

 

[steve_dune]

So there shouldn't be any play in the bolt even with the extractor out of it? I measured it today and was getting at least .050 of movement with a round chambered. All I should have to do to adjust the headspace is press the barrel in and drill the hole to the next biggest size then pin it?

 

[Malikovski]

I'll check next time I'm in the shop, but I don't believe there's any play in any of my 7 AKs. You really need to invest in gauges to tell for sure.

You are correct about fixing it if it's long. You remove the old pin, press the barrel in until it the bolt will close on GO but not NO GO, then ream a new hole and press in a new pin. Reamer is better than a drill bit, and you want the pin to be, if I recall, 0.002" larger than the hole you ream.

I wish someone else would weigh in here. I have built a few but am no expert.

 

[Big Az Al]

Ak fire problems

Most of AK's I get to work on have the same problem.

Green Steel cased ammo! gunked up chambers!

The AK's I have dealt with have a neet feature, if the bolt is not cammed all the way closed the hammer hits the bolt carrier causing miss fires! A gunked up chamber will not let the bolt cam all the way closed!

So if the chamber of an AK does't look like nice white metal, that is it a tan, brown or even just frosty looking, clean it really well. A large brass brush, lots of oil and a drill supply all elbo grease needed to do the job!


As far as reaming an AK Barrel??????? IMHO ROFLMAO HA HA HA HA!!!!!
HARD CHROME ruins reamers!!!!!!! And a barrel that is not Hard Chromed, IMHO is cheap JUNK!

Even the Romainian AK's that people laugh off as junk have hard chromed barrels!

 

[Big Az Al]

I should have posted this........

Are you talking the bolt handle moving, or the bolt head having been removed from the bolt carrier, moving that much? If it is carrier moving that much as long as the camming surface are in this gun, only if the carrier seated all the way home would I worry.

The bolt head should start to close, on the no go gauge, but not seat all the way home.

Without a guage using as many types of ammo as possible, whatever tape you use I would go to figuring the bolt head closing freely on what I figure to be up to .012, is safe to fire, maybe hard to reload for.

For those of you that .012, NO WAY. get an MI Garand field manual and check the Maximum head space, and then figure the 30-06 is loaded to higher pressure then a 7.62 X 39

 

[JA]

First thing remove the firing pin and clean the firing pin hole in the bolt. Use a good degreaser and pipe cleaners or wire to make sure the hole is completly clean.
According to SAAMI voluntary industry standards used by commerical manufacters of Sporting Arms and Ammunition the minimum headspace is 1.252" and maximum headspace is 1.262". So doing the math 1.262"-1.252"=.01"
1/16 of a inch is .0625" so if with a cartridge chambered the bolt not the carrier moves 1/16" then the headspace is more than 6 times what it should be.
Denting the primers is normal as the firing pin is loose in the bolt and when you chamber a cartridge the bolt is stopped when it hits the back of the chamber but the firing pin keeps moving foreword till it is stopped by the primer of the chambered cartridge leaving a dent in it.

To check headspace the most field exspeadent(quick) and cost effective(cheap) method is to look on the package your printer paper came in and it will list what pound paper it is. Then go to
http://www.paper-paper.com/weight.html
check the chart to see how thick the paper is. Cut a strip off the sheet of paper that is as wide as the base of a 7.62x39mm case .443". Then cut the strip into some .443" squares. Lightly lick a square of the paper and stick it on the bottom of a cartridge then lick 2 more squares and stick then on the first one. Give your spit a few minuites to dry and chamber the cartridge. The bolt should not fully lock if the headspace is correct as each piece of paper is at least .0032" or thicker depending on the poundage of the paper.
If the headspace checks out ok then check the lenght of the firing pin.
At the range load a cartridge and point the rifle down at the ground. Give the back of the receiver cover a good whack with you hand and then slowly rasie the rifle level and pull the trigger. If the firing pin is too short the rifle won't fire.

 

[steve_dune]

The dent in the primer is a pretty deep dent. I thought it could be from the headspace being off.

I put 3 layers of masking tape on the back of the round and still had atleast .035 of movement in the bolt.

 

[JA]

The depth of the dent in the primer depends on the brand of ammo. Commerical ammo will have deeper dents than military surplus ammo.
Your rifle has too much headspace.