K-31 Ka-boom

Mother of God, I never thought I'd ever see this!

K31 receiver alloy is so tough I have to use carbide tooling to even get a bite on it. To see it shredded like that is pure horror.......the most wicked shrapnel I can think of! Man, I'm glad the shooter is still among the living!!!!

This is a post from the Swiss Rifles forum, cross posted. Hope I'm not breaking any rules. They get into more depth on this Kaboom.

http://theswissriflesdotcommessageboard.yuku.com/topic/5631

Claven's comment is very interesting. He obviously has metallurgical expertise.



And once again, I will point out these guns are NOT battle tested ;)

That receiver looks like the pics in Hatcher's notebook of blown-up M1903's that had improper heat treatment making the steel too brittle. That failure is too crystaline to indicate failure due to plastic deformation as we would see in a modern gun, or even most guns made after 1918. It looks to me like the steel is martensitic. It should not be. The grain should look like a mix of austentitic and pearlitic steel that underwent plastic failure in a typical blowup.

Glad to hear you are OK.
 
Would have been interesting to give it to a university metallurgy department as a student project (three years on) for analysis.
 
when i saw the pics it showed that the bolt wasnt locked because the serial #s didnt seem to be at 12 oclock, the nightmare happened , in my opinion, when the cam follower pin broke. too much of a k31 newbie to really know? but its my opinion. personally im gonna check those serial numbers just to make sure...a little rapid fire here and there though once in a blue moon maybe. B2
 
I personally feel the problem is, 22grns of a magnum pistol powder in a rifle case with lots of air in it, a recipe for a detonation.

+1

This used to happen a LOT with inexperienced revolver cartridge reloaders stuffing a mere 5gr of 2400 or similar in a .44Mag case.

I'm pretty sure that I don't need to explain surface detonation as opposed to columnar deflagration to anybody on this forum.

tac
 
+1

This used to happen a LOT with inexperienced revolver cartridge reloaders stuffing a mere 5gr of 2400 or similar in a .44Mag case.

I'm pretty sure that I don't need to explain surface detonation as opposed to columnar deflagration to anybody on this forum.

tac

I wouldn't mind if you did. I know that too much air/too little powder can cause kabooms, but it'd be good to have it explained in depth. Understanding the theory rather than following rote rules is always better in my opinion.
 
And once again, I will point out these guns are NOT battle tested ;)

That receiver looks like the pics in Hatcher's notebook of blown-up M1903's that had improper heat treatment making the steel too brittle. That failure is too crystaline to indicate failure due to plastic deformation as we would see in a modern gun, or even most guns made after 1918. It looks to me like the steel is martensitic. It should not be. The grain should look like a mix of austentitic and pearlitic steel that underwent plastic failure in a typical blowup.

Glad to hear you are OK.

I thought the same thing about the metal at the fracture although not in as much detail, it looks just like a crappy socket extension when it snaps from being overly hard. I too am glad you were not hurt.
 
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