I tend to agree with the idea that the receiver had a error and discarded into the reject pile, however, does the following picture look familiar?:

Taken from "The Krag Rifle Story", 2nd Edition, Subcaliber Attachments, page 96.

You know in U.S. coin collecting there's an "Coin Error" classification.  Wonder if there is one for Springfield Krag errors made by the Springfield Armory?  Not including modifications made post production.

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