This question is mainly directed at rifle loads relative to pressure levels for cycling ARs, especially with short barrels, but also a consideration for accuracy relative to optimal barrel time.
So I know that a boolit needs to be soft enough to obdurate but hard enough to stick together at a given velocity/twist rate. To what extent does hardness effect friction between the boolit and rifling. I seem to remember reading that jacketed loads generate higher pressure for a given powder because they are harder. Is this correct?
I guess I'm not clear on whether a jacketed boolit would be slicker despite being harder (meaning peak pressure is reached sooner?) While the cast boolit would take the rifling more easily but be "stickier" the length of the barrel, so a more even pressure curve?
Short version: I know a harder boolit requires higher pressure to obdurate, but can a harder alloy also generate higher pressures?