Suka said: --(in case anyone wants a good light load, my practice load is a 405gr cast over 28gr IMR 4198(cheap and accurate))
This is what is so good about the 45-70 Marlin. There is just no end to accurate loads, from anything faster than 4350, right down to the Unique, 4227 class of fast powders. Those fast powders make deadly accurate, light loads that are fun to shoot. Actually, I haven't tried 4350, maybe a good charge of it would also be good!
I've tried eight or more powders and there were none that were bad. I've tried lots of different power levels and it is interesting to see how they work. Every load that is higher power than another, just shoots a bit higher at 100 m, but always dead in line.
A good example is the IMR 4198 mentioned above. Suka says 28 grains is a good load with 405 cast bullets. I've mostly been using 420 grain bullets, and settled on 33 grains as a very accurate, medium light load, about like the 405 grain factory in recoil. I went up to 43 grains of 4198 and it was really a good group, but five shots made my head ache! So just look at all the possibilities with only 4198. Yes, I have a Limbsaver on my 1895 model, so the shoulder doesn't hurt, but it sure rolls the head, when you load it up. People who have said it has a "different" recoil, are correct.
In short, the 45-70 in a good rifle is a handloaders dream.