As far as I know, if they were factory loads, they should have already been loaded to safe levels for use in a Krag.  Remington and Winchester ammo has always been manufactured to acceptable velocities and pressures.  I would shoot any remaining factory rounds as-is. 

Another handy tidbit for reloading:  If you're concerned about your primers moving, use some primer sealant.  I loaded some Italian Ordnance 10.4 mm brass that was converted Berdan primed.  This very rare round has no current production ammo or brass... so I converted old (but good condition) Berdan cases to accept Boxer primers.  The primers were slightly looser than they would have been had the cases originally been Boxer.  I used good primer sealant, and since this was an old Italian revolver with very tight headspace, I was confident they would be safe... and I was right - the sealant really did the trick and the primers never moved!  I now use primer sealant on all of my rifle ammo, Krags included.