I started using a .45-70 to kill deer around 20 - 25 years ago. I started and stayed with the 400 grain Speer flat nose. I guess I've used some of the 405 grain Remington bullets as well. I started with Varget and it seemed the more I used the more accurate my Guide Gun was. I stopped at a load that was about all I wanted of a good thing. While it's no real fun to shoot, it will put three of those 400 grain Speers in about 1 1/4" and I can kill a deer easily out to about 200 yards. It seemed that the hot rod loads would sometimes make the Speers come apart in the early years. I think they hardened them up a bit though, with hot loads in mind and they seem not to act so much like varmint bullets now as speeds approach 2000 fps.I wouldn't hesitate to use that set up on anything in NA.
If I still had the time and facilities to play with stuff like I used to, I'd get about a 400 grain mold and go cast, albeit with smokeless powder.
I am a big believer in using "normal" for caliber bullet weights, seldom going much above or below the accepted norm. I personally have never had any interest in 300 or 350 grain bullets in the .45-70, but for those who do, more power to you.
