Versatile actor, Gary Oldman, known to Harry Potter fans as Sirius Black, stars in the upcoming action thriller Hunter Killer, alongside Gerard Butler. For this film, there really isn't any better way for filmmakers to faithfully capture the essence of military life than by deferring to those who have had the first-hand experience of it — and that's exactly what Gary Oldman thought about his military advisor Russell Coons.

"Russell is...he really knows his stuff. It’s a very very specific, very technical, kind of movie so to it's an absolute necessity to have someone here who has actually been on submarines and on ships, knows the protocol. So he is invaluable. You need someone like that around."