FTF doesn't have a ballistics forum and somehow I didn't think it should go in Ammunition & Reloading. Its too, dare I say it, entertaining.
It is a link to an astonishing 10 minute video of bullets hitting targets filmed at 1 million frames per second.
The very first shots display what appears to be the (metal?) target liquefying when hit. Subsequent shots merely show the target matter fracturing.
There are some shots through ballistic jelly. Im guessing the deformation is due to the molecules of jelly immediately in front of the slug expanding from the heat and then being pushed aside into the surrounding jelly, which in turn push other molecules, and so on.
Somewhere in the videos middle, are slugs in flight being hit by something else (a BB?).
Toward the end are shots displaying the jacket of an (armor piercing?) slug being stripped from the slug like a banana peel as the slug goes through the target.