Years ago we tested my old vest out at the shooting range when no one else was around.
45 ACP FMJ, stopped with no penetration throught any layers of kevlar.
45 ACP Hollowpoint, stopped with no penetration throught any layers of kevlar.
45 ACP Magsafe, through the front out the back, penetrated all layers of kevlar.
22-250 rifle, through the front out the back, penetrated all layers of kevlar.
22-250 rifle, through the front out the back, penetrated all layers of kevlar and 1/8 steel plate insert
Bullet proof is a misnomer