I always go for the double lung shot with big game that is broadside. If you shoot for the shoulder you may not break both front legs. It's amazing how far a deer or larger animal can go with 3 legs before it bleeds out.

Through the lungs, I can't remember a deer or Elk going more than 100 yards. Plus, you're more likely to clip a major artery/vein to/from the heart in the lungs. In that way, the animal is losing large volume of blood quickly and loose of O2 to the body and brain brings the animal down sooner.

As my grandpa Victor used to say, too. Don't go chasing the animal down as soon as you shoot it, even when you think it's a fatal shoot. A deer at least is more likely to run a ways and lay down, to bleed to death if it isn't being chased. He'd always smoke his pipe for 15 minutes or so after shooting big game animal before starting to track it. A very successful hunter he was and wise in his own way.

Bottom line. Heart/lungs are a higher probability of quick clean kill... imo

minnfinn