According to RatedRR, the "XS1 is the largest-calibre Precision Guided Firearm available today." This video demonstrates how its automatic targeting system works over 1123 yards. That's 1km. This is the kind of stuff we only imagined in science fiction movies only a few years ago.
The rifle's automatic targeting system — Tag Track Xact — can hit targets 1200 yards away using algorithms that compensate for the wind speed. Once you put the reticle on the marked target, boom, the rifle fires on its own and hits it — all while streaming video of it all to Android and iOS phones, where it can be recorded. I cringe at the thought of thinking not if but when are we going to see the first recorded kill of a human being in some war or urban shooting scenario.
And yes, the video seems sponsored by HTC, who wants you to think about their phones the next time you think about buying a phone to destroy with your long range precision rifle.