We had an expired level II soft body armor and we wondered how it would hold up to different pistol calibers. We started off with a 45 caliber from a Glock 36 and we shot the vest a total of 20 rounds. We went to inspect the vest after 20 rounds and the vest looked like it hasn't been touched at all, but we weren't surprised knowing a 45 is a slower and heavier bullet than a 9 or 40. We then proceeded to use a 9mm out of a 4" Walther PPQ and shot the vest a total of 20 rounds. We inspected the vest and found no markings at all with a 9mm and the vest still looked like it hasn't even been touched. 

We started packing up when I realized I brought a Ruger Mark III  and I had a bulk pack of Remington 22LR Golden bullets. I don't know how many rounds we shot, but after shooting the vest we went to inspect it and we saw bullet holes. We wanted to see how much of the vest it penetrated and to my surprise it was only a few layers away from actually penetrating all the way through.