.243 vs .308
I don't want to discourage you, but, as they say "practice, practice, practice". The .243 will make this easier. Besides, the .308 was originally designed as a 200 yard cartridge to be used in auto rifles. Although an accurate cartridge, and one that has surpassed the intentions of its creators, it hasn't the power for shooting at 600 to 800 yards.
Lastly, research your rifle and scope choices well as shooting at long range requires excellent equipment. You have a challenging goal that will be hard to reach if you use inadequate equipment. Good luck!
Clemmer, you've got to crawl before you walk. This involves plenty of shooting and becoming quite proficient at 100 yards. I agree with nab that the lesser recoil of the .243 will help you become a better shooter, and its certainly good coyote medicine. When you can center a paper plate regularly at 300 yards, you can then move to 500 yards. If a gust of wind blows shortly after pulling the trigger, a miss is inevitable at these ranges. With proper bullets, the .243 is an adequate deer cartridge provided the bullet is properly placed. I, for one, am darn sick and tired of tracking poorly shot deer by users of too small a caliber who don't place their bullet appropriately.
I don't want to discourage you, but, as they say "practice, practice, practice". The .243 will make this easier. Besides, the .308 was originally designed as a 200 yard cartridge to be used in auto rifles. Although an accurate cartridge, and one that has surpassed the intentions of its creators, it hasn't the power for shooting at 600 to 800 yards.
Lastly, research your rifle and scope choices well as shooting at long range requires excellent equipment. You have a challenging goal that will be hard to reach if you use inadequate equipment. Good luck!
