That's why you have this thing called a ballistic app, that let's you put in the actual weather condition and variables of which you zeroed your rifle in at 300 yards, and then they have another thing called current weather conditions when you shoot any other day or place of the year. It does all the computing for you! Gee, what a concept huh...The difference of a 100/200/300 zero isnt crap. It's all personal preference based on where, how, and what a guy is hunting or shooting and comfortable with. Nothing more, nothing less. And for all the guys who cant remember how many clicks they've dialed and where they're at etc, that seems more like a personal problem than anything...