5.56mm SA vz-58 suffers a set back

[armoredman]

Today when I tried to fire the rifle, I got the dreaded *click*. A close inspection revealed that the very tip of the firing pin had somehow broken off, leaving a concave crater that was ALMOST long enough to reach the primer - it left little half circles on one side of the primer. The amount of metal lost is very small, but just enough. When I broke down the bolt, (that's gonna be a pain to put back together - good thing I know a gunsmith.), I saw that the firing pin was a slightly different design that the pictured one in my 7.62x39mm hi cap manual. I wonder if that was the issue, as the rifle has performed perfectly for about 2000 rounds, give or take a few hundred, between the factory and me. I fired only factory or mid range reloads, nothing hot.
I sent in an e-mail to Dan at Czechpoint, and I don't doubt this will get taken care of toot sweet. Hey, compared to the Glock slide breaking while firing in front of me, this ain't nothin'! I can't wait to get it back into action - I have a bunch of lovingly prepared hunting loads to try!

[Stevo]

I've seen three or four reports of the same thing on 5.56 guns in Canada.

Do you have pic of the firing pin? I'm curious if it's different from the 7.62 pin.

[armoredman]

Well, I haven't stripped my 7.62x39mm vz-58 bolt down to compare firing pins, but this one differs from the one pictured in the hi-cap manual that came on disc. I don't want to break a bolt down if I don't have to - I'll lose something in this carpet.
I couldn't get the macro settings just right, so we have multiple pictures, but you can clearly see the concave area where a tiny bit of metal broke off.







I am no metallurgist, wonder how this would happen.

[Varickm]

Does the firing pin use a spring?

[armoredman]

No, the only spring is in the extractor, actually.

[Stevo]

Differs how? There are two versions of the 7.62 pin that I've seen, one have three "flutes" and the other having four.

[Varickm]

Is there a step-down at the point where it broke?

[armoredman]

Stevo, the one in the manual has four, this one has three. Dan will be able to say if they are the same.
Varick, you can see where it broke off, that's the rounded very front end of the firing pin. More like a chip than a break.

[Varickm]

I guess it's just me, but the top photo looks like there is a step-down before it extends out a little further.

[armoredman]

The possibility exists, certainly, that there was a small nub that extended a wee bit farther - it's hard to tell.

[Stevo]

Stevo, the one in the manual has four, this one has three. Dan will be able to say if they are the same.
Varick, you can see where it broke off, that's the rounded very front end of the firing pin. More like a chip than a break.

Thanks. The two styles are interchangeable on the 7.62 guns.

[Varickm]

Wouldn't a slight step-down prevent an efficient transfer of energy? I don't know...maybe it's just the photo.

[armoredman]

The 7.62x389mm version had a "flare, like a collar, where this one is pretty straight, and the actual "pin" section is longer on the 7.62 version - wish I knew how to capture an image off a PDF to show the difference.

[armoredman]

Well, DUH! I looked closer at the firing pin - what's left won't fit through the channel. Must have been some smaller diameter section that snapped off.

[armoredman]

AND, as expected, Dan got right back to me first thing this morning and is shipping a redesigned stronger firing pin as I type this.
Sometimes I love saying, "Told ya so!" 

Only thing left to worry about is fumble fingered me putting it back together right....  Did I tell you the US Navy used to let me handle high explosives???