I was born, raised and spent all of my life (save for my 13 years in the service of our great US Naval Institution) as a troll.  I've spent exactly 2 weeks in da Yoop - a family trip to Copper Harbor when I was 13!  I'd LOVE to go back though...

As Chuck said, even well worn Krag barrels can achieve amazing accuracy.  Some guys shoot cast out of their shot out "Tack Drivers!"  Also, after slugging the barrel, you might find that shooting oversize - .310 or bigger may garner excellent results!  I'm no expert, but I would consider re-boring an absolute last resort.