 And here's the deal. With a full metal jacket bullet, that's a non-expanding bullet. So when you shoot into tissue, what you start out with is what you end up with. If you've got a 45 caliber bullet, it's going to make a 45 caliber hole. If you've got a 9 millimeter bullet, which is a 35 caliber bullet, it's going to make a 35 caliber hole all the way through.