Introduced by Winchester in 1952 and adopted as a military round in 1955, the .308 Win. was formed from the .300 Savage, but it’s essentially a .30-06 short or, as some say, a 'thirty-not-six.' It has the same head and body diameters as the .30-06 on a case roughly ½-inch shorter. The resulting smaller powder reservoir means the .308 Win. suffers a 100- to nearly 200-feet per second (fps) speed loss to the .30-06, depending on bullet and load. You may notice this as increased drop and drift, but elk won’t notice any difference when hit. A high ballistic coefficient (BC) 180-grain spire point launched from a 24-inch barrel at 2,600 fps by a .308 should retain 1,500 ft-lbs of kinetic energy at 400 yards. Not that it has to carry that much energy, but 1,500 ft-lbs is widely accepted as a minimum impact standard for elk, so we’ll stick to it. I can assure you, however, a bullet hitting an elk with just 1,000 ft-lbs of energy isn’t going to bounce off, and the .308 Win. carries that to 650 yards.