Ammo is available.  Check Graf & Sons.  They have both loaded ammo and reloadable brass (something that has been sorely lacking in the marketplace until very recently) under their label.  Also, Remington ammo with a 180 gr Core Lokt bullet is available from some sites, as well as frequently found in places like Cabelas, Bass Pro, and the occasional gun shop.

SAVE YOUR BRASS!!!  If you don't normally reload, you might consider getting into it for the Krag, as loaded ammo is seasonal at best, and getting harder to find these days... AND is rather expensive!  There are no shorter of people on this forum who will get you going in the right direction when loading for Krags.