It would take a 71mph xwind to move the bullet 56', see the table in #78. The effect of the wind only depends on the bullets ballistic coefficient. That's the ratio of the drag of a std. projectile/actual bullet. In this case it's ~0.46, see #75. That means, for any given bullet with constant B.C.(ballistic coeff.), the effect of the wind is linear with wind velocity. A bullets B.C. may change slightly throughout a velocity range, but the effect is normally small. In this case the shooter had to consider those changes to hit his target.
The only num. that seems close to 56, is the 60" drop between 800 and 900 yards, assuming he's sighted in exactly on target. The reporter probably got lost in the explaination.
I guess I'm going to have to holler "uncle." Based on your tables, the shock wave (or perhaps the spiraling effect for the slug?), must be causing a bizarre susceptibility to crosswind effects after about 300 yards. (This is not easy to see, perhaps, but I graphed the points.)
At some point between 300 yards and 400 yards for the case of a 40-mph crosswind, the slug apparently goes bonkers with the wind effects. By the 600-yard mark, it is moving offcourse a lot faster than the wind is blowing it sideways. It covers the last 300 yards in .064 seconds, but it moves 19.6 feet sideways over the same very short interval. That means it has an average sideways velocity over that distance of over 200 mph. This is a whole lot faster than the wind is blowing, by a factor of five, of course!
So, if the tables are correct, then the law of the conservation of energy is telling us that the wind is not directly accelerating the bullet to the side. The bullet is NOT behaving like a golf ball would--not at all. Somehow the crosswind is stealing the forward energy of the bullet and converting that kinetic energy directly into a rather incredible rate of velocity at right angles to the forward direction!
I frankly don't understand this phenomenon. As I said in one of my earlier posts, maybe the features of the shock wave--or the gyroscopic nature of the bullet--involves something which my model can't address. I will now freely admit that this seems to be the case.
(Hmmm....energy transfers at right angles does sound like a gyroscopic phenomenon of some kind to me!)