If you are talking about a true lung shot with no CNS contact...
NOTHING....
They nearly always run 20-70 yards, whether you shoot 'em with a 22-250 or a .338..
IF the bullet hits or PASSES CLOSE TO the spine, they will fall down and usually bleed to death before they can regain thier feet..
If shoulders are involved they may fall down...
If you really want them to fall down RIGHT NOW shoot them somewhere other than through the lungs....Like the shoulders or where the neck joins the body....