Question, "Will straight wheel weight bullets fill the "a bullet soft enough to expand beautifully" requirement at those speeds?
Absolutely, as long as they are the old style clip-on wheelweights, and not modern zinc ones or soft lead stick-on weights. Add a pinch of tin to aid mold fill out. Nose shape has a bearing too, obviously. A hollow point expands better than a flat nose, a flat nose better than a round nose, and a round nose better than a spitzer.
It's always a good idea to make a chamber cast with any Krag you pick up. Throat diameters varied all over the map, and since it's throat diameter that drives bullet fit (not groove or bore diameter) it pays to know what yours is and size the bullets accordingly. Realistically expect anything from .309 up to .313", and I have a friend who swears his is .314"
