I have not seen a Krag Bolt, (personally), that had an obviously 'cracked' Lug.

I recall seeing a picture, on the internet, of a lug with a crack, visible at the rear base of the Lug, where it meets the bolt-body. (I do not have a copy of this picture).

I have seen at least one bolt that had a 'seam line' on the bolt-body. It ran on a 'curve', from the lower-rear corner of the bolt-lug past the bolt's ejector groove to the 'Bolt-Face Flange'. The Bolt belonged to a friend and he wisely replaced it, before shooting his Krag. We could see and feel this Line with a fingernail, but, we could not visually tell if it was the 'surface skin' hiding an underlying fracture or simply a surface irregularity left during manufacture (unlikely - IMHO).

Attached is a picture of a 'fractured' Krag bolt that recently sold in a batch of parts on ebay. (I was unsuccessful in my bid to get it).

The picture may be indicative of one way a Krag Bolt-Lug might fracture. (I imagine the broken or 'sheared' bolt section remained in the action until the bolt was opened. I would believe there had to be and indication the Lug was failing, before this complete separation). 

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