Welcome to the wonderful world of "Hmmm, maybe I should get one of these for X amount of $"! Shooting even moderatly long range requires a really accurate rifle/load combo that most people don't luck across in a factory gun, a range finder that works consistantly to the ranges you want to shoot and either bullet drop/drift charts that reflect (accuratly) your rig or a ballistics program with the needed info either printed out or portable, ie laptop. Figure out what you want to hit and how far away you want to hit it and take it from there! Armadillos @ 800 yards is going to be a great goal and quite an achievement to do with consistancy. Take out your favorite outfit and start shooting (targets) and see what you can hit and from how far away. Did I mention that you should bring lots of ammo and a cleaning kit? When I'm playing with long range gear, I bring along a trail bike or 4 wheeler so I can ride to and from the target and avoid being tired and distracted while shooting. You'll soon learn the limitations of your shooting ability and your equipment. Once you know how far away you can consistantly hit something the size of an armadillo in the kill zone, you need to start shooting something like half gallon milk jugs from different distances to get the distance compensation and wind doping down pat. After you figure that out.... Go for it! As you find you have individual problems, post them on the forum and there are plenty of experts that will happily lend their expertise to solving your problem be it wind doping, lack of rifle/load accuracy, needing a better shooting bench, whatever.
Welcome aboard and have fun!
All it takes is One Good Shot!