For what its worth, I have been loading the Speer 270 grain GDSP for many years now. The powder that works best for me, (in loads for my 1894 Marlin, with 20 inch barrel) ,is 21 grains of H110. I get a pretty consistant 1540 to 1550 fps, and exellent accuracy. This load has accounted for a lot of hogs, and several whitetails.
Nemo Me Impune Lacesset
"The trouble with our liberal friends is not that they're ignorant; it's just that they know so much that isn't so.".........Ronald Reagan