OP should know that Type II body armor should protect against most pistol rounds. Type III-A will protect against heavy pistol rounds. Type III will protect you all the way up to even NATOs 7.62x51 cartridges, which virtually nobody shoots up a school with. Type IV can eat huge rounds, but you'll probably look like a forgetin turtle all day.
You gotta know this stuff if you go to school in America OP, it's basic knowledge.