I always go for the double lung shot. If you take out both lungs, tracking should be very minimal (unless its an elk; they can go FOREVER with no air in their lungs). With 2 different caliber rifles (.30 and .257), the farthest I've ever had to track an animal was 50-60 yards with both lungs hit. I've had a couple drop right in their tracks, but that was attributed to the hydrostatic shock of the bullet (Barnes TSX). The one time I took out a deer's shoulder (.30-06 @ 200 yards quartering away) it was a bloody mess and I hated wasting the meat. I wasn't trying to take out its shoulder, it was just part of the shot angle. Neck shots are pretty much quickly lethal due to the shock to the nervous system, taking out a major artery/vein and, sometimes, the wind pipe; however, you have much less room for error. I'm with SCOFFIN in that double lung shots seem to be more humane in addition to giving you more wiggle room for shot placment in the vital zone.