8mm Mauser AD upon lockup?

[Chindo18Z]

A friend has a sporterized 8mm Mauser (German WWII bringback) which has never demonstrated mechanical problems (been in the family a generation or two).

He experienced two accidental discharges at the range while locking the bolt forward on surplus Greek Army 8mm. This only happened when using this particular ammunition and only twice out of aprox. 10 or so rounds.
Other (premium factory) ammo performed normally.

What might be causing this? Headspacing / OAL of bullet?

I'm not well versed on the bolt face / firing pin setup for this weapon. Could this problem indicate worn firing pin parts or springs?

Has anyone here had a similar experience?

Wondering if this sounds like an ammo problem or a trip to the gunsmith...

 

[davera]

Sounds like it could be a bolt problem. Since it's a WWII bringback, I'll assume it is a 98k. The bolt partially cocks on open and it sounds like camming it closed may release the firing pin.

Don't know why it would do it on the Greek surplus but not other premium ammo. It would not hurt to disassemble and inspect the bolt.

http://www.surplusrifle.com

Will tell you how do do that.

 

[RedeyeGunner]

That was my first thought, a broken firing pin or weak firing pin spring. The other ammo you shot may have had harder primers also, which might explain why it only happened with the Greek stuff.

 

[rcmodel]

It's not the ammo.
If it was firing before the bolt was locked, your friend would be seriously injured.

It is not uncommon for shade-tree gunsmiths to cut down the cocking piece or the sear on military bolt guns to make the pull shorter and/or lighter.

Also to cut the sear/trigger spring a few coils for the same reason.

Also to grind off the "double-hump" on the trigger to get rid of the military two-stage pull.

What you have is not enough sear engagement.
The slop in the bolt and cocking piece allows the striker to jump off the sear and fire accidentally.

You will need some new parts to repair the damage already done by some amateur "gunsmith".

BTW: Don't shoot it anymore until it is repaired.


rcmodel

 

[RedeyeGunner]

If its the sear, wouldn't it also fire using other ammo?

 

[Spiggy]

yes, but then you'd be having a combination of problems to deal with

 

[rcmodel]

The way a 98 works, the firing pin cannot hit the primer unless the bolt is locked.
It has to be slipping off the sear as the bolt is just about closed to hit the primer at all.

That it's only happened with one kind of ammo doesn't mean it won't happen with another brand some other time.

I'd have a gunsmith check it out just to be safe.


rcmodel

 

[MilsurpShooter]

IIRC The only time a firing pin protrudes from the bolt head in the K-98 is when it's in a fired condition. Perhaps the ammo has a softer primer then other types and this is what has made the problem noticeable? Even then with a round that fails to go off in a situation like this your friend most likely would be complaining about failure to fire or double taps on the ammo...

Anyway, sounds to me like a mechanical problem with the bolt. Have him strip the bolt down to it's pieces and compare how they look with how they're supposed to look. Good photo reference can be found here:

http://www.surplusrifle.com/shooting/mauserboltdisassembly/index.asp

Regardless of if the photo's show you something or if everything looks normal, have it taken a look at by a gunsmith before firing it again

 

[Chindo18Z]

Thanks to all for the replies.

Looks like my friend's Mauser needs to be examined for excessive "bubba" gunsmithing.

No danger of it being fired at the moment as both the owner and myself are in Iraq and the Mauser is back at home.

I will pass on everyones' advice. I expect he will be taking it in to his gunsmith.

 

[rcmodel]

Another thing to check.
It may not have altered two-stage military trigger parts in it.

If someone sporterized it years ago, it may have an old Timmeny, Jaeger, or other after-market adjustable trigger.

Some of the cheap ones (not Timmeny or Jaeger) where made from a pot metal castings for the housing.
They tend to crack & crumble after 40 years or so.

Or, it could just be set too light, and is jarring off when the bolt closes.


rcmodel