I can neither confirm nor deny any connection to that story.
Interestingly though, I used to be one of the top 1000-yard shooters in this area, and I actually know the people who made the barrels for that type of rifle he used in the movie.
It's a CheyTac .408, and that type of rifle probably still holds the 2500-yard accuracy record, as far as I know.
It's about the best choice, if you plan to accurately hit targets at more than a mile.
It comes with its own hand-held ballistic computer, which has sensor inputs for distance, wind, temp, direction, angle, etc, and automatically calcluates bullet trajectory, and displays the necessary scope adjustments on the little display screen. So, you get your data, make the scope adjustments, and fire.
An experienced marksman with that rifle could hit a man-sized target nearly every time at a mile and a half distance.