A Pope is to be assassinated, but the FBI doesn't have the knowledge to go about doing it. In comes gunnery seargeant, who has. After surveying possible sites for the kill, he reports to the Bureau ideas he has came up with. The Bureau carries out his ideas, but at the same time frames the SG for it, claiming he's the one who carried out the hit. But someone at the Bureau smells a rat, and goes abt his own investigations as to what really happened. The story from there goes abt narrating how the SG gets justice done for him, and clears his name. Involved were a Colonel and a Senator. Who died in the end, rightfully.

That in short, is how the movie Shooter went. Nice! Full of action, shooting, bombings and what have you.