In the November 2007 issue of Louisiana Sportsman magazine there is an article titled "The Shoting Doctor Is In." This is about a Baton Rouge gynecologist who prides himself in taking minimum 500 yard head shots on deer. Working from memory I think he has 2 Savage rifles in 308 for anything out to 600 or so and over that he will go to his 408 Cheytac I think is built on a Remington action. If memory serves me his longest shot was a rangefinder verified 1200 yds and longest head shot on a doe at 800 yds. It is definitely doable, but I would spend alot of time practicing at the ranges you intend to shoot.