Krags are fascinating beasts... and just like all entities, different Krags like different food.  Some people do very well with 150, 168, and 180 gr spitzer bullets.  Some shoot 150 gr RN and even 130 gr RN bullets with great success (I have a friend that routinely shoots 290 or better in CMP matches with his 1896 shooting 150 gr RN).  Many others do better with cast spitzers.  My Cast Bullet rig is a 1898 cutoff sporter in a Bishop stock with a Kraghaus Long rail and an LER scope.  Shooting NOE 311365 185 gr Spitzers, I can almost shoot 1/2 inch groups at 200 yards.  My rifle LOVES 220 gr Hornady RN bullets.  It's really a matter of playing with different loads until you find the one that works best for you and your particular Krag.