Just got a .45-70 1895. Got some 300, 350 and 405 grain Laser-cast bullets to load. Using trap-door class loads, I run out of sights at 100 yards with the 300 grainers - though not with the heavier ones. The open sights at maximum elevation put the 300's with 32.0/5744 at POI (on top of the bead) at 50 yards, but 3" or so low at 100.
The 350 and 400 grainers shoot higher, as they would with a handgun but, if it works the same as a handgun, I think the only way I could get the 300's to print higher would be to reduce the velocity.
Suggestions?