I only shoot gas checked cast lead bullets in my two Krags.  The grooves on both my Krags are right at .310 so I size my bullets to .312.   For 200 yard CMP matches I use the Ed Harris load of 16 grains of Alliant 2400 powder and the Lyman 314299 bullet which weighs 205 grains from my wheel weight lead.  I've chronographed this load before and it's about a 1400 fps load.  It will keep them in the 10 ring of the 200 yard SR target if I can hold them there.  It's a very mild load and cool to fire, wait a bit and then hear the thump of the bullet hitting the cardboard target backing.