To STOP a charging Griz, you better be shooting to break shoulder bone.
You’ll never get through the skull and you’ll be half eaten before he dies from a heart shot.
I have seen several bears in the 400 lb range that have been head shot through and through with a 215 gr hard cast at 1050fps.
Out of a short barreled 41 mag. An angle shot not hitting the schull dead on could lead to a bullet not going when it is surpose too but that could be with any thing.