Today a friend shot a deer three consecutive times in the heart and then twice in the lungs. That darn deer never dropped. Rifle was a Win. M-70 with a 2.5-10 Nikon Tactical, ammo was loaded with 168 A-Max bullets, 45 gr. Varget in Hornady brass. The buck was standing at 600 yards broadside.
Now what I failed to mention the deer was made of AR500 steel, and his lungs swing 90 degrees to the left when they are hit, then return to position. Same for the heart, only 90 degrees to the right and back. Damn fine shooting, the heart is smaller than your fist.
Shooting at a critter target is great practice, better somehow than round gongs or little man shaped targets. I just ordered a coyote with swinging vitals, that will be fun since everyone likes killing coyotes.
These targets are not cheap but they are very well made and really fun to shoot.