Isn't the pressure against the bolt face on the .45-70 much less than the pressure of the .444?
The SAAMI max for the .45-70 is much lower than for the .444, due to the fact that the .45-70 is a carryover from the black powder era.
If loaded to the same pressure, bolt thrust will be higher with the .45-70 due to the larger diameter of the case head/rim area.
I personally don't see the need to go past 35.5 Kpsi with the .45-70. If I need a faster large diameter, heavy bullet, I go with a bigger case. If I need flatter trajectory, I go with a better platform for that. Recoil becomes a factor, too.
The .45-70 is very good at killing big animals at shorter ranges, and the .444 with 300 grain or heavier bullets is a monster, too. There ain't much I can't kill with a .45-70 loaded with 425 grain LBT hardcasts at 1650 to 1700 fps. Same with a .444 and the proper bullets.
