I created a simulation of the T64 Armor vest from WWII/Korean War era out of 1/8 7075 aircraft aluminum and 8 layers of ballistic nylon. The test samples were able to stop 9mm luger, 9mm nato, .45 ACP and .357 magnum JHP at point blank range. The sample could not stop steel jacketed 7.62x25 tokarev FMJ. 7.62 tok has the ability to penetrate some level 3a body armor, even the interspetor OTV or kevlar helmets.
.357 magnum JHP