Krag Bolt Failure

[Whig]

I found this short piece in a 1955 issue of American Rifleman. Interesting analysis. I really have seen very few true examples of a cracked Krag bolt like this although it has been talked about for over 100 years.

[Blueheeler]

I wonder what the shooter considered "fairly hot"?

[butlersrangers]

Thanks Whig, this should be a KCA "sticky".

This 1955 photo shows where a 'crack' will occur.
(A 'wrinkle' may appear in a bolt's 'surface skin' following this 'crack pattern', but, concealing the underlying crack).

IMO - It is a good idea for Krag shooters to own a spare 'new old stock' bolt, or two.

Also, it is good to inspect Krag bolts at each cleaning and to have a 'Field' headspace gauge.

[Culpeper]

Could it be 44,000 is a "hot" load for the cartridge? The Ordnance Department drawing from Frankford shows 38,000 as the max pressure.

[butlersrangers]

It is good to have an idea of 'what to look for'. I suspect a faulty Krag bolt will give some early warning signs, if heeded.

I have never owned a Krag with a visibly 'cracked' locking-lug.
I have one Krag bolt, that I did 'retire', because of a suggestive & subtle 'wrinkle', that makes a slight "C" curve, from behind the lug to the bolt-face flange.

BTW - Grandpa's Gun Parts has thousands of unissued model 1898 bolts for around $65, each. These will fit all Krag models - Cheap Shooter's Insurance!

Attached photos show faulty bolts, viewed on eBay and GunBroker, years ago:

[Whig]

I can't believe that many reloaders would overload a Krag case so much, at least on purpose, to blow a chamber or crack a bolt. These bolts weren't that weak that they cracked with normal use, as history has shown. It seems to be over pressured loads that are the risk. I have examined well over 100 Krag bolts and have never found any cracks or over pressure damage that I have recognized. They should all be examined properly before use. I'm sure there are some out there. It just isn't common.

[scottz63]

Hmm... I had better look mine over a bit more carefully.

[waterman]

I cracked the bolt on my Bannerman M 1896 when using a load recommended in Ken Waters "Pet Loads" book. If you have headspace issues, it is pretty easy to do.

[Blueheeler]

So this thread leads me to to want a Krag field guage, but they are out of stock, would a 303 british work? I think rim thickness is the same.

[MooseNugget]

Not sure if we still have it but we had a thread concerning the same topic a number of years ago. I believe some of the content discussed had to do with magnetic particle inspection for the determination of metal crack/stress fractures. Neat testing method that revels problem area not readily apparent with the naked eye.