I've watched afew videos about body armor being shot with different rounds, yes it will stop a 45acp / 10mm/44mag but that enegy is still transfured to the target which may break a after a 44mag in that area.
I believe it was Richard Davis of Second Chance who used to shoot himself in the chest point blank with a 44 mag, then turn around and shoot bowling pins. You can probably find the videos on you tube. I believe they also did one with a .308. Here's one: