There is a lot of info on-line about this subject. Some are even in the easy to understand video format. I've even spoke to a couple Pro Hunting Guides that agree with the on-line information. Based on my experience (and the fact that I have a thick head), I have a tendency to not totally agree. When I hunted in Pa., there was a lot of uphill/downhill shots. Anywhere from 30-50 degrees. The shots were anywhere from 50 yards to 130 yards. The first experience was with a Vintage Military Japanese 7.7 at 50 yards, with iron sights, downhill at about 30 degrees. That was the only center-fire rifle that I owned at the time. The bullet drop should have been a moot point. I aimed center mass chest area and the point of impact broke the deers spine just above the shoulder. I thought it was me but couldn't understand because I didn't recall pulling the shot. Didn't matter, deer was down. Another experience was with a 270 at about 125 yards. This time, I had a 3X9 optics set on 9. The angle was about 35 degrees downhill. Again, bullet drop should have been minimal at that range. Again, using proper control, I pressed off the shot. The deer dropped like a rock. Again, the bullet broke his spine above the shoulder. Again, it seemed strange but the deer was down. The third experience was with a Marlin 30-30, from a high bluff, shooting downhill at a 45 degree angle if not slightly more. I was using iron sights. The estimated distance was 100 yards. Again, bullet drop should have been minimal at that range. It was a quartering shot with the deer coming at me. I pressed off the first shot and the deer froze in the "saw horse" position with his head lowered (nose almost touching the ground) and his legs spread evenly in all four directions. He just stood there while I sent (embarrassed to admit) 10 more rounds his way. That required reloading my 336 (twice). Long story short, I finally concluded that I was shooting over his back. At that point, I forced myself to aim about 10" low, below his body line. That shot dropped the deer. Later investigation showed that the first bullet took a small chunk out of the top of his head, between the antlers. He was KOed on his feet. No information on-line tells you to shoot 10"-12" low at a 45 degree angle with a 30-30 at 100 yards. I swear to you, that is what it took. Gravity has that much effect. Even using on-line calculations, the distance would have been about 50 yards and with iron sights, mounted on the barrel, the comp wouldn't be more than an inch or two. I couldn't find it but the best explanation that I have seen is a video of a guy using a wimpy 8' Fly Rod and holding it at different angles to explain the basics. What are your thoughts and/or experiences????? I know we have some military marksmen on here. Give us some insight, please.