From director Henry-Alex Rubin, the action-drama Semper Fi, which means “always faithful,” follows Cal (Jai Courtney), a by-the-book police officer who’s also a Marine Corps reservist, along with his close-knit group of childhood friends – Jaeger (Finn Wittrock), Milk (Beau Knapp) and Snowball (Arturo Castro). When Cal’s reckless younger half-brother Oyster (Nat Wolff) gets in a bar fight that leads to an extreme prison sentence, loyalty leads Cal to risk and sacrifice everything for family. During this 1-on-1 phone interview with Collider, Aussie actor Jai Courtney talked about why he wanted …