Q:I don’t know what you think about mid-range trajectory figures, but Ican see little practical advantage in the average hunter knowing howhigh his bullet is going to be at mid-range. It’s quite a while sinceI studied the subject of trajectory and may have forgotten most ofit, but I do remember that “height at mid-range” and”maximum height of trajectory” are not the same, and thatthe latter is not reached until a point well beyond mid- range.Bearing this in mind, I believe that knowing how high a bullet isgoing to be at mid-range is of dubious value at best.
A:If it were not for the retardation of the bullet by the atmosphere,the maximum height of the trajectory would occur at exactly one-halfthe range. However, under actual conditions the maximum height of thetrajectory comes at a point slightly beyond mid-range and is slightlyhigher than mid-range height. However, in the field the difference isso small as not to be of any practical importance. Take for example,the .30-06 firing a 180gn bullet at 2700fps, the average height ofthe trajectory over a distance of 100 yds happens at 50.9 yds. Thedifference in the height of the trajectory at mid-range from what itis at this point is too small to worry about. Even when we extend therange to 200yds., the maximum height of the arc comes at 103.8 yds.The height at this point is 2.89″ as against 2.86″ atmid-range. Obviously, as the range gets greater so the differenceincreases, but over average hunting ranges the difference is of nopractical importance. But I disagree with you about it being uselessto know what the mid-range trajectory of your load is. Shooting atvarmints I don’t want the bullet to rise more than 2 inches atmid-range, or rise more than 4 inches with a big game rifle, andalways sight-in to ensure this. I think that you are just nitpicking!