I know from experience that our vests (Point Blank IIIA) will stop the following:
5 - 5.56x45mm
1- 12ga slug
2- 12ga 00Buck
10- .40S&W 180gr
We had a vest that was past its expiration date, so we took it to the range for a bit of "testing". Vest was hung on a rail at the end of the range, not placed over a semi-solid object. All shots were fired at a distance of 5 feet. Shots were fired, in that order, into a single vest, no trauma plates.
Now, all that being said, that's a heckuva lot of kinetic energy. Your insides would likely be turned to jelly. Regardless, I would not want to be shot with anything, vest or not.
"To preserve liberty, it is essential that the whole body of the people always possess arms, and be taught alike, especially when young, how to use them." -Richard Henry Lee, Virginia delegate to the Continental Congress, initiator of the Declaration of Independence, and member of the first Senate, which passed the Bill of Rights.