AK headspace question

[CavemanSteve]

It would seem that the hole in the bolt face that the firing pin comes through on my WASR 10/63 has somehow become too large. This appears to be allowing the firing pin to come out too far and causing pierced primers. Still assessing it, but I think that is what is going on. So the question is, if that actually is the problem, can I switch out the bolt and get back to shooting or do I need to be concerned about head spacing? Also, any good sources for an appropriate replacement bolt?

[CavemanSteve]

I took another AK apart (an RPK, actually) and compared the holes. A punch that easily fits into the WASR hole will not fit into the RPK hole. Am I correct in my assumption that the tolerance of the hole size is important and possibly causing my issue?

[Danjal]

It's probably not the hole size. Check your protusion on your firing pins and your edges where it contacts the primer. Sometimes they square off or are knicked from the factory. Otherwise if they're too long they can pierce the primer. You want about .055" +/- .005" protruding with the rear of the pin flush at the rear of the bolt.

And what ammo are you using? US spec stuff has been known to have soft primers.

FWIW also, post a picture of the bolt faces so we can see the firing pin holes, or use some drill bits to measure them.

[CavemanSteve]

I dropped it off at my gunsmith to get the headspace checked just to rule that out, so no photos for now. No valcanoing on the bolt face.  This happened with Golden Tiger ammo. The smith had a hard time getting the bolt closed easily with the headspace gauges. Unfortunatly I was a bit pressed for time and had to leave it with him. We did notice that the gas piston was slightly bent, which MAY have effected the bolt carriers travel. We'll see.

The firing pin is brand new from APEX. New because a pierced primer shot the last pin out the back of the bolt and bent it into an S shape. Firing pin retainer pin also had a small section sheared out of it. Both were replaced, but the pierced primer happened again on the first round fired. This rifle has had somewhere between 3 and 4,000 flawless rounds previous to this happening over the last week or so.

[Danjal]

You could have a batch of ammo with soft primers. If it persists once it's back swap your ammo.

Hopefully your Smith stripped the bolt to check headspace. After that if it's tight it could be a CIP Vs SAAMI thing depending on his gauges.

[AKBLUE]

Check the firing pin protrusion.  Adjust accordingly.

http://www.akfiles.com/forums/showthread.php?t=178660

[Danjal]

AKBlue, are AKs known to have varying fp lengths based on country of origin? Or are they all fit to rifle/standardised length?

[AKBLUE]

The firing pins are generally standard.  But on some or if the pin is virgin it may need/require fitting a few .000's.., though not common,.
Virtually all things AK are not manufactured to USA/western spec. in fitment.  The reason for barrel journal markings on the barrel and serialized parts unique to each firearm.