As I have conducted ceveral test on bodyarmour for the use of UN in Bosnia (russian origin). 222, 357, 44 mag, 9mm, 30-06, 38 special, shootguns, you name it. I have seen the result with my own eyes and conducted the shooting as well.
I will claim that a 44 mag, will not shoot trough even the Class 2 west (without the keramic plates or steelplates).
It will knock the guy on his *** but not kill him, disable him (it might disable him, but might is not prefarable).
Theres one cure, aim for the head or the legs, but this is a true phycological thing, no one will do it. When facing a criminal with bodyarmour, the 44 mag, is totaly useless. I rather have a 9mm in that case. It has a biger chance of penetrating.