Is this why my AK47 is having light primer strikes? [PICS]

[andrewj]

I think I've narrowed the problem down to the firing pin but I want a second opinion.

Click pics to enlarge:

You can clearly see the pin and rear of bolt have some wear from the hammer strikes. The pin is slightly mushroomed but not enough to restrict forward movement.







This is how far the pin extends to the rear due to gravity



Here is the pin with a dummy round in the chamber





To me, it looks like the pin protrudes enough for the hammer to effectively strike it but what do I know? I recently bought the K-Var maintenance kit that has a bunch of replacement parts. I replaced the hammer spring and tried replacing the firing pin but apparently I bought the wrong kit or something because the pin I got was too thin and too long.

So until I get a new Romy firing pin, what are your thoughts? Do you think I'm on the right track?

[Ryan in SD]

Head space is good? If its too loose the chamber closes with out the back of the bullet fulling engaging the bolt face.

Hammer spring could be too weak, any binding of the hammer as it travels?

[andrewj]

Originally Posted by Ryan in SD

Head space is good? If its too loose the chamber closes with out the back of the bullet fulling engaging the bolt face.

Hammer spring could be too weak, any binding of the hammer as it travels?

I guess I should give some more info

My AK was originally a PAR-1 pump action. I swapped out the pump action barrel assembly for that of a Romy G. I had to replace the PAR-1 bolt carrier since it didn't have a charging handle or piston. I am using what I believe to be a Yugo carrier because its what I had lying around. After headspacing, I took it out to BLM land and had zero issues whatsoever. It work perfectly for about a year. Ever since, I have been having some light strikes using all sorts of ammo. The only type of ammo that worked flawlessly was American made brass cased stuff.

So to answer your questions, headspace is good. The hammer spring had been swapped with a friend's hammer spring during an outing just to see if it had any effect. It didn't. Today I swapped out the hammer spring with a new one that came in the K-Var maintenance kit I bought. I didn't really expect it to matter but it couldn't hurt.

[4thSBCT]

have you been dry firing it? or bump fire?

[andrewj]

Originally Posted by 4thSBCT

have you been dry firing it? or bump fire?

I probably bump fired it once or twice throughout its life. As for dry firing, not really. I'll dry fire it to drop the hammer after checking the chamber now and then but I never dry fire repeatedly or gratuitously just for the hell of it. Judging by the pictures though, I think it almost looks like I have.

[Jak1]

Check the firing pin to hammer fit. A PAR-1 I had was off so much it would only fire if the firing pin sat just right. If this is the case, a dremel could fix it right up.

[andrewj]

Jak1, could you elaborate on "firing pin to hammer fit". Does that mean there should be solid and square contact between the two?

[Jak1]

The hammer should be perpendicular ( at a 90 deg. angle ) to the back of the bolt and the firing pin with the hammer down. My Par-1 brand new "over rotated" and only caught the firing pin if it was straight up and down.

After a closer look at your pictures, you can see where the hammer is not hitting the firing pin square. That is why it has mushroomed the back of the firing pin and slightly dented the back of the bolt.









I think

[andrewj]

Yeah, that's what I was thinking. Since my hammer isn't hitting the pin square, it may not be transfering all of the necessary energy to the pin to ignite the primers.

As you were saying, perhaps taking a file to the hammer's face and changing its angle so that that I get a perpendicular strike may solve the problem.

[Jak1]

A dremel worked great on mine.

[SVT-40]

Timing seems to be the issue. along with head space. Loose head space along with improper timing could cause a issue. Hammer follow can cause all sorts of "issues".

I built a semi auto out of a PAR. I used the original bolt carrier and welded on a charging handle. I kept the original barrel as I could not see the need to waste a perfectly good barrel.It humus like a kitten.

Do you still have the original bolt carrier?

Here are a few photos of mine.

[andrewj]

Originally Posted by SVT-40

Timing seems to be the issue. along with head space. Loose head space along with improper timing could cause a issue. Hammer follow can cause all sorts of "issues".

I built a semi auto out of a PAR. I used the original bolt carrier and welded on a charging handle. I kept the original barrel as I could not see the need to waste a perfectly good barrel.It humus like a kitten.

Do you still have the original bolt carrier?

No, I sold off all the PAR-1 parts long ago.

I checked the headspace after pressing in the barrel. It was the first and only time I have ever used gauges but it seemed straight forward enough. The bolt closed on the go gauge and didn't on the no-go so I figured it was a done deal. Hell, the rifle worked perfectly for a year or so, so I assume headspace isn't an issue.

Would using the Yugo carrier cause any problems? Are there differences between Romy and Yugo carriers that can affect timing if used in the wrong rifle or wrong bolt?

At this point, the next step I'm plan to be taking is A) change the angle on the hammer's face so I get a square strike, B) get a new Romy firing pin.

[WTSGDYBBR]

Using a different carrier will cause a issue. Using a different bolt would be a issue. Tell you the truth you need to check the head spacing with the Go and No Go gauge with that new carrier. I can see by using a simple new bolt would cause a issue. You may need to fine tune it do you have go and no go gauges ?

[andrewj]

Originally Posted by WTSGDYBBR

Using a different carrier will cause a issue. Using a different bolt would be a issue. Tell you the truth you need to check the head spacing with the Go and No Go gauge with that new carrier. I can see by using a simple new bolt would cause a issue. You may need to fine tune it do you have go and no go gauges ?

No, I don't have any gauges. I had been looking to get some on loan not too long ago but didn't get any bites

[SVT-40]

Something to think about most Yugo AK's were built with 1.5 mm receivers. Romanian's were built with 1 mm receivers. So a Yugo carrier would have slots in it for the 1.5MM receiver to ride in. Using a Yugo carrier in a Romanian 1mm receiver would mean the carrier would be loose and allow it to move vertically. If you look at the tail of your bolt you can clearly see where the top of the hammer is hitting the bolt. If the bolt were being held lower then maybe the hammer would be striking the tail of the bolt squarely

Do you have another Romainan AK? Maybe you could try swapping the bolt carriers To check how the bolt lines up using a carrier designed for the 1mm receiver.

I'm not recommending you shoot the rifle with the different carrier (although you probably could safely) Just check the geometry to see if the bolt is held lower.

Can you show a picture of the hammer resting against the bolt?

[andrewj]

Originally Posted by SVT-40

Something to think about most Yugo AK's were built with 1.5 mm receivers. Romanian's were built with 1 mm receivers. So a Yugo carrier would have slots in it for the 1.5MM receiver to ride in. Using a Yugo carrier in a Romanian 1mm receiver would mean the carrier would be loose and allow it to move vertically. If you look at the tail of your bolt you can clearly see where the top of the hammer is hitting the bolt. If the bolt were being held lower then maybe the hammer would be striking the tail of the bolt squarely

Interesting observation. That certainly would account for the hammer striking the upper half of my bolt and firing pin.

Originally Posted by SVT-40

Do you have another Romainan AK? Maybe you could try swapping the bolt carriers To check how the bolt lines up using a carrier designed for the 1mm receiver.

I'm not recommending you shoot the rifle with the different carrier (although you probably could safely) Just check the geometry to see if the bolt is held lower.

No, I don't have a Romy carrier handy. What, if any, problems could occur trying a different bolt carrier in my rifle? As far as i see, it shouldn't affect anything. Or did you just mention that so I dont sue you in case my rifle blows up

Originally Posted by SVT-40

Can you show a picture of the hammer resting against the bolt?

I'm out of town right now but I can get some pics up by Thurs. or so. It's safe to assume that my hammer is only making contact with the upper half of my bolt, judging by my pics at least. I'm definitely anxious to verify that though.

[SVT-40]

Using a different carrier SHOULD not be a safety issue. My caution was just "In case".

I just noticed something "unusual" while looking at your photos. I noticed the tail of your bolt looked unusually short. As it was not sticking very far out of the rear of the bolt carrier.

Compare your photo (modified)


To a "normal" Romanian bolt when locked.



So I took my PAR out and measured the bolt..... It's about 1/4 inch shorter than a standard AK bolt.... News to me!!!



Standard Romanian bolt above. "PAR" bolt below.


The reason I am probably not having the same issues as you are having, Is. I'm still using the original Romanian hammer which came with the rifle. So I checked it. It has a different profile on it's face so it strikes the rear of the bolt flush and not from the top.


SOO if you still have the original Romanian hammer you could place that back into your rifle, or use it as a guide to modify the hammer in your rifle so it strikes the bolt and firing pin flush. Or just file the area of the hammer which strikes the bolt tail so it strikes the tail of the bolt properly and flush.


Photo showing hammer / bolt engagement of my PAR rifle.

[WTSGDYBBR]

andrewj . If you want to meet up send me a pm and bring your riffle . I'm not far past valley view off the 91w . I have Go and No Go Gages we can get it checked out with .

[andrewj]

Wow, excellent work there Detective SVT-40! That's is definitely something I would have never caught.

I'm fairly certain that I don't have the original FCG anymore. Since that is likely the case, I'll just grind my Tapco hammer as already planned. At least this way I won't have to mess with the 922r compliance nonsense again. Still, we won't know immediately if the carrier and firing pin are contributing factors but I doubt they are.

and I suppose my rifle used to work as desired because the firing pin hadn't been damamged yet. After repeated partial strikes on the same small surface on the pin, it was damaged to the point where the hammer just didn't have enough firing pin to hit anymore.

Sweet, I can't wait to get home and tinker around with it now. Thanks for everything!

[andrewj]

WTSGDYBBR, p.m. inbound