Parashooter wrote on Feb 19^th, 2012 at 4:41am:

If you haven't tried .308" jacketed bullets in your Krag you might be surprised how well they can shoot. That is, after all, the nominal bullet diameter of GI and commercial .30/40 ammunition.

Agreed. I would at least try that before I went with cast/gas checks.  The original .30 Government load was a .308, 220 Gr. RN bullet.  Try it and you might just find that your Krag really likes them.  The throat was designed with them in mind.