I've been shooting a long time. As a kid we would often dig in the sand backstop to find the deformed slugs from what we had shot. The bullets were always mushroomed out and very deformed. Yesterday, we were out at "the farm" and had put some soda cans in a low spot of the field to shoot at. When we went to pick up the cans, we saw a couple of the spent bullets laying there. A) I was surprised that the bullets didn't burrow themselves deeper into that plowed field B) I was VERY surprised that the bullets had not deformed AT ALL. Take a look: These are 115 grain full metal jacket UMC. So the question becomes, How hard does something have to be in order to make a jacketed bullet deform? Or won't a fully-jacketed bullet deform that much?