I am working on a .260 Remington. The ballistics table says I need 25.5 MOA for 1000 yards. I am adding a Vortex Viper that says it has 75 MOA of elevation adjustment. The longest range close by my home is 1200 yards. Using 1200 yards as a max range and using a 100 yard zero, what if any slope would you order on a base? I would think if I get too much slope, I wouldn't be able to zero at 100. Maybe I am wrong in that thinking. This is my first long range rifle, so I'm not sure.