If its big...shoot!
Its really going to depend on the deer. They are as varied as You, I and the next guy. I would guess 22 inches is average on a mature buck between the ears. Question is, are they relaxed, pinned forward or slightly back.
Depth on the animal depends greatly. I've seen those that look like a hereford, and those that are all guanted up. Honestly, look for symmetry, and tine length and if its out past the ears, and its massive enough to warrant your liking, pull the trigger.
Characteristics of a mature buck besides mass in the antlers. Look how he sags in front of a big blocky chest. Roman nose, skull cap colorization, and more
