I was watching Mack test the MP7-A1 recently,
and when he had previously tested the MP-5,
he fired at the bullet resistant vest. But, when he tested the MP7-A1, he fired at the helmet on the dummy. Most helmets are not designed to completely stop a bullet, but are instead meant to protect the head from impacts, such as a fall. I am sure that the MP-5 would of penetrated the helmet. I am not sure what would of happened if he shot at the vest.