I've noted that mindset myself, Kraig, and for some time. It's sort of like the magic that haints single-shot pistols. Folks who scoff at the 30-30, .35 Rem or .375 Winchester in a rifle, somehow see them as 350 yard Pronghorn or Buffalo slayers, in a pistol.
We should keep in mind that no matter what we do, we aren't going to make the 45-70 a flat shooter. As long as we set some self-imposed limits, it doesn't need to be. 350+ grains of lead, trundling along at (give or take) 1300 fps, will bore a big hole through an awful lot of meat & bone.