Krag Bolt-Lug Crack

[butlersrangers]

You don't see one of these very often.

It's interesting to see the pattern of cracks on this Krag bolt.

It gives an idea of what to look for.

[FredC]

BR,
Is this in your possession? Did you take the photos? Like you say we do not see many.

[butlersrangers]

It's not mine, nor my work, it is on ebay and kind of interesting. (I just borrowed and edited the pics).

Here are some more pictures of failing and failed Krag Bolts. They are pictures that I accumulated over the years.
I don't think I own a cracked Krag Bolt?

I am not trying to cause worry.
The stories of these Bolts and what happened are lost in time.

The Krag is a very 'polite' action, but, no point in getting complacent or taking things for granted.

IMHO - It is just prudent to check "Old Betsy" before and after shooting.

It helps to know what to look for and where.

(A 'new old-stock' model 1898 bolt only costs $60, from Granpa's Gun Parts)!

[FredC]

That last one would be helped by a better close up, but I think I see a finer grain structure near the surface and coarser structure near the center. If so that is as expected with case hardening. The coarse structure in the center lends toughness and resistance to cracking. A denser finer structure near the surface and especially where cyanide was added gives it wear resistance and higher tensile strength. Any good bolt can be ruined by accident or abuse. Your squib could have led to this if not noticed or you were a neanderthal and tried to shoot the stuck bullet out.


Attached photo shows correct heat treatment in a tractor axle that was abused with 80 hours on the machine. The tractor axle was hardened by a different process but does show the fine structure on the outside and coarse structure inside.

[donki1967]

Interesting and impressive! I will check my bolt this morning...

[donki1967]

Nothing wrong with my bolt.
Thank you for your advice.