I must concurr with Capt Kirk -
please note that the pressure is measured in "pounds per square inch".
on a flat based .44 bullet the area acted upon ( assuming a .445 bullet after squishing into the chamber) is .1554 square inches.
the nose of the bullet will present significantly more surface area. since the nose is sort of paraboloid surface area is .40886 sq in,
so the pressure will be 2.6 times that of the flat based bullet!
If , with black powder with a flat based bullet , you are getting a chamber pressure of say, 10,000 psi, by loading with the "point down" you could be seeing as much as 31,500 psi against the "base"
by contrast a roundball ( for pressure purposes we are looking at a "spherical section" rather than a true half-sphere ) we have a surface area of .2512 square inches and would see a pressure of ~ 16,000 psi on the "base"
remember, your milage will vary with the actual surface area, numbers, etc.
but I would not chance it.