Where did this with the monometal bullet come up? The only mono i can remember are of pure lead.
And why the need to educate about pressure signs in a double when no one has urged to go "max pressure". Flatend primers are a sign of pressures that is far from the 45/70 pressures that has been the subject here.
No one started to give load data before you went on a rampage on the 45/70 and said it wasnt even possible, the reason no bullet type is refered to in the data are becourse at this state its not important, the possibility to throw any bullet at the speeds that you say are not possible is the issue, now you try to tell us that ist not safe and all as it will perhaps throw the gun of face as its so worthles.

And you are trying to make it sound as the others on this tread has no or little idea of reloading,
in my book thats really bad manner.

Now at what speed does a 458 hard lead bullet equal the penetration of the 375HH with a solid.

Btw, the flattend primer is a totally crap way of telling of overpressure even on the rifles you recomend it on.