The military does. Magnus was the one that came up with the theory for what’s know as the magnus effect when studying artillery while gyroscopic drift may sound similar but is another issue. Artillery is another story entirely, also keep in mind these are area effects weapons. As for snipers, the military got rid of spin drift for a long time then brought it back when software became standard equipment as far as its teaching. It’s not something that is of common concern in small arms due to its relatively small yield in deviation in most military operations. Most salt dog snipers don’t worry about it. You do get to learn about it when you go to follow up courses. Artillery you have a kill area of 150 ft and cas area of 300...now I was not an arty guy but as a guy who’s called for fire I’d imagine they don’t want to let a 155 drift off 20 mils at 13 miles... As to the equation and why it’s hard, you should read the article. I don’t speak nerd, they call people like me a knuckle dragger for a reason, and I don’t like copying and pasting other people’s work. But it has to do with the, as stated, a (quasi)linear formula working to solve a non-linear equation. The litz formula tends to work well with burger vld bullets for obvious reasons and is “close enough.” While they can see the spin drift using equipment, to calculate it is another story. To use a standard value, would require each bullet company for each bullet to have a value for every twist and every speed (tof) for it to be as simple as that. They have used “super computers” in the form of 6 DOF models and PRODAS. The over all conclusion is that for the most part, 2% of drop tends to be closer to the reality of the bullet impacts (in gyroscopic drift) at range then a linear formula. I suspect because there is no accurate way of calculating a scale factor for assorted bullets and thus the nerds need to rely on 6 dof models.