I'm aiming from 1,227,017,716,320 feet away. I'm trying to hit one target about 2' wide. Originally, we only set this system up to handle maybe a couple of yards worth of variance at distances of a couple hundred miles. Statistically, when tele-porting around the Castle, we wanted to only be off a few millimeters. Any variance we wanted on the "free air" side of a surface to prevent popping into existence in the same space as another solid object.
Now stretch that "fudge factor" out to millions of miles, and being off by half a continent isn't surprising.
I've got a few filters I'm working on to get down to that .0000000000000001 of a degree that should allow me to hit what I'm aiming at.
Collecting the data from the first two shots allows me that control.