I don't think you're familiar with the difference in power between "high power" handgun ammunition and "common" centerfire rifle ammunition.
To put it another way, even if a soft vest could stop a rifle bullet from penetrating (which I do not believe possible), the wearer would likely die anyway from blunt force trauma.
As for death due to shock wave, that's what trauma plates are designed to diffuse and absorb. And if such prevented penetration, the laws of physics dictate that the total foot-pounds of energy hitting the target would be less than that existing at the muzzle. Rounds of small mass do not impart a great deal of energy to a target.
The problem is that a round tumbling through soft tissue creates a shock cone that contains energy capable of rupturing blood vessels and hollow organs (e.g. heart, stomach, intestines) and disrupting vascular solid organs such as the spleen and liver, not to mention the semi-solid lungs. The effects of shock on the CNS (outside of the brain) also disrupts nerve impulses which control heartbeat and respiration....