Back in the day, the gun rags at the time were all about kinetic energy. The popular opinion back in the 60s was 1300 foot pounds was the minimum energy needed to put a deer down . Since that time two things have occurred: 1) Bow hunting has become much more popular 2) Bullet technology has improved by leaps and bounds Research this subject on the internet today and you will see some "experts" say that kinetic energy doesn't have all that much to do with it. People reliably kill deer with bows that produce around 65 foot pounds of kinetic energy. Some of these same folks advance the argument that terminal ballistics are what kill deer. Assuming correct bullet selection and proper shot placement, some go on to say that as long as the bullet is still turning out the velocity within which the manufacturer has designed the bullet to operate, you get a dead deer every time. Granted bullet selection and shot placement are probably worth more than kinetic energy, but I'm wondering what the practical answer is from folks that have actually walked the walk. I hunt on ranches in Western Oklahoma where distances can stretch out. I've killed dozens of deer over the years and most were taken at distances under 300 yards. Most of my deer were taken with stuff like the 270 Winchester, .25-06, 7MM-08 and the 308 mostly with Nosler Ballistic Tip bullets of appropriate weight. I also own several belted magnum rifles. I'm not recoil sensitive either. I was a competitive rifle shooter for better than 20 years. All of my shots were dead on the money...high shoulder and neck shots. When the animal was quartering away, I lined up on the off-side shoulder and sent the round diagonally through the rib-cage. I can hit deer well out past the 400 yard mark, but I've passed on many shots out around 500 yards because of concern about bullet energy and out of respect for the animal and the sport. Have I let stuff walk that I should have taken a shot at? Just to make it interesting, the 100 grain Nosler Partition bullet in .243 is rated to expand at 1800 fps on the low end. Does the terminal ballistics idea make the .243 a 500 yard deer round? I have no preconceived notions on this subject. I'm just wondering if I'm holding on to an old idea that has been long outdated and irrelevant. Your thoughts?