Sierra's 70 grain blitzking with the plastic tips removed will cycle through the magazine of my 25-20 with acceptable COAL. Removing tips of the blitzkings is a PITA, but they give good speed and terminal performance.
75 grn Speer's or the Rem 86grn round nose should be available on gunbroker, but they aren't just everywhere, or available any time of year.
Neat project, good luck with it.
