It doesn't matter how many bullets were fired or how large their calibre, you won't see entrance wounds, exit wounds or any blood at all anywhere on or near their targets. Shooting victims simply fall down, leaving neat and clean crime scenes. The only way you can tell a shooting victim from a poisoning victim is that the latter will usually be grimacing. It's almost as if they were made of sawdust instead of flesh. A subvariety of this trope allows for a small amount of blood, looking more like a ketchup stain from a particularly sloppy lunch, to mark the location of a wound.