This question came up on another Forum. I didn't care to get involved on that forum, but, the OP had an interesting dilemma.

Described Situation:

Recently purchased, nice looking, original finish, U. S. model 1898 Krag rifle.
(The owner is a general collector of U. S. arms and wanted one Krag in his collection, to shoot).
The bore cleaned up Very Good, except, the last 1/4 inch at the muzzle. That part of the bore is badly pitted to the point rifling is non-existent.
During initial Range Session, at 50 yards, this Krag spread shots over a 6 inch group.

The OP is considering having the Krag barrel counter-bored 3/8" to get to good rifling and create a sharp 'crown'.

If this would destroy the value of his Krag, he would rather just sell it, as is, and look for a better shooting Krag.

(Assuming the OP used good ammo, is a competent shooter, and the Krag is original and collectable):

What are the thoughts of KCA members?

FWIW - (If it were mine and the bore looked really promising, I would likely go the counter-bore route).