Krag Bolt Failure

[butlersrangers]

In regard to headspace gauges:
Not an easy answer.
Some .303 gauges will also work with the U.S. Krag.

A few years ago, we found that some Clymer .30-40 H-S gauges, were not manufactured to PROPERLY function with the Krag's bolt-face.
The gauge rim-diameter was too large. The Clymer gauge would hang up on the flange that surrounds the Krag bolt-face.
This caused totally false readings. The base of the gauge was not in contact with the actual bolt-face.

(I have 'bumped' this old thread and it appears above in 'ammunition, reloading, & shooting, etc' as "Problem with Chambering ...").

The first attached photo shows the problem Clymer gauge and the second photo shows how a gauge should contact the Krag bolt.

[Culpeper]

What is the chance rim of the bolt was dinged in a minute amount and the gauge a thosandth too large or even a half thoundth? Could it be the bolt rim was out of round?

Maybe it is an optical illusion but there seems to a problem in photo 1. I see plenty of room around the gauge on the left and right but it is "pinched" at the bright spot which cause a hang up.

Just curious about what I am seeing.

[butlersrangers]

The Clymer gauge rim was simply too large in diameter to fit properly against the Krag bolt-face.

The 'flange' on the front of the Krag bolt is thicker and angles slightly inward as it connects to the face of the bolt.

A headspace gauge with an oversized rim diameter and sharp corners may begin to enter, but, can hang-up inside the flange and give a false reading.

(My second photo shows a .30-40 cartridge and a 'no-brand' headspace gauge, both of which easily meet the Krag bolt face with no chance of hanging up on the inside of the flange).

[scottz63]

All 3 of my Forster gauges fit easily down to the face of my Krag bolt. Rim diameters on them measure between .529 and .531

[Culpeper]

A headspace gauge with an oversized rim diameter and sharp corners may begin to enter, but, can hang-up inside the flange and give a false reading.

Yep. That would do it. Especially the sharp corners not being chamfered.