'Doco' - "Delmarva Peninsula": I learn something new, everyday! I had not heard that name before and I live in a State that has lots of Peninsulas.
In regard to your Krag: If you reload, back-off your Resizing Die a turn or two and Neck-Size only. There is no point in needlessly working your Brass.
It is possible that someone 'lapped' your bolt's Locking-Lug so that the bolt Guide-Rib would make contact, at its rear, with the receiver. This was an old gun-smith practice and thought to make the U.S. Krag receiver "stronger". (The Norwegianand Danish
Krags were built that way). In reality, this adds several thousandths of 'free travel' to a U.S. Bolt and results in additional 'case-stretch'.
It is easy to check this by removing the whole 'striker mechanism' from the bolt and inserting the 'bare' bolt into the receiver. There should be a few thousandths of an inch clearance between the rear of the bolt rib and the receiver. If the rib contacts the receiver, it has probably been 'lapped'.
A 'new' 1898 Krag bolt can be obtained for around $55 and will function in all earlier Krag receivers (and will restore the guide-rib clearance).
I agree with what others have said: "Enjoy your Krag as it is". In reality, it is worth more for its parts (and play value) than as a 'Whole Rifle'. It is not a candidate for restoration.
Attachment 69161