I usually shoot for the upper shoulders. With a .308 at less than 150 yds they drop most of the time. Shoulder meat is fed to the dogs after blowing through both shoulders:s1:

I am red/green color blind and for this reason I shoot a Browning 7mm mag. I always take the neck shot if available, high shoulder if neck isn't available. The large caliber will shock the spinal cord even if you miss the bone in the neck. Always drops em in their tracks. A 25-06 is a very nice caliber and certainly does the job, but unfortunately if one runs I need help tracking it so I opt for the big bore rifle.