>Besides, it was demonstrated on MythBusters that bullets
>don't really cause human bodies to "fly."
Mythbusters weren't using 50s.
There's nothing magic about .50BMG. It's just a small arms cartridge, albeit a large one. It won't send human bodies flying through the air, or explode them like prarie dogs. It won't even come close to doing these things. It will make the body twitch more so than whatever rifle was used by Mythbusters, but that's about it.
.50BMG from a rifle length barrel is, approximately, a 650 grain bullet at 2800 fps.
If you want to make a human seem like a prarie dog, a better start would be a 25mm auto cannon as mounted on the Bradley. A 2300 grain projectile at 4400 fps.