You use the rifle as designed: if it was designed to use clips, you use them. The Krag was designed to use loose ammunition. However, I just set fast time at 2 matchs, one using a Krag, the other using an 1895 Winchester. The ability to top off the Krag between shooting positions, as well as the ease of loading, makes it as fast if not faster than clip loaders. The double row Mills Belt helps a lot. In fact it's absolutely vital, as it allows you to grab handfuls of cartridges, as opposed to one or two from a single row belt.
Last years Expansion match saw the top 2 finishers using Krags, beating a bunch of clip loading 1903's.
The Winchester? Dumb luck, dummy rounds and practice, practice, practice . . . again, the double row belt is vital.
Well down the 1st page of "Care and Feeding of the Krag" there is an entry on how to speed load a Krag.