Depart123
Exactly. Those two loads are the historical standard in this cartridge.I like 3031 powder and 150gr or 170gr bullets. I figured out early on why it's called 3031... 30grs with the 170 bullets, 31grs with the 150 bullets.
I abandoned the 150's early on. There just isn't enough velocity gain to make any real and usable difference in trajectory, so you might as well have the extra sectional density for penetration. Plus, it has seemed to me over the years that more rifles (especially Marlins)favor the 170 grain bullet as far as accuracy goes.