With ceramic plates installed, I doubt it would penetrate. I doubt the wearer would get up after being shot, either. I have shot railroad backer plate at 100 yds. with 375 and 458 heavy FMJ and soft points. 7.62 NATO penetrates more, 5.56 about as much, and 50 BMG goes through and keeps going so far you don't have the energy to retrieve it. On a hard target, there is an advantage to having a smaller-diameter meplat projectile and higher velocity--less area to disperse the force.
