Based on the book series written by former Navy SEAL Jack Carr. The series consists of seven books so far: The Terminal List, True Believer, Savage Son, The Devil's Hand, In The Blood, Only The Dead & Red Sky Mourning.
In one of the preparations for Pratt's role, Jack Carr (the author of the original story) gifted Chris Pratt the novel "Once An Eagle" by Anton Myrer, which is a large historical fiction piece carrying the themes of World War 1 to Vietnam, while also expressing a case study in leadership.
Co-stars Chris Pratt and Patrick Schwarzenegger are brothers-in-law. Pratt is married to Schwarzenegger's sister, Katherine, both the children of Maria Shriver and Arnold Schwarzenegger.
The tomahawk used by Reece is the WK RnD Axe. It is a collaborative design between Master Bladesmith Daniel Winkler and skilled Sayoc Kali martial arts trainer Rafael Kayanan. The handle design provides a standard grip position, as well as a secondary close quarter grip that was developed to emulate the feel of a handgun grip.
One of the operators in the brief scene at the beginning of the first episode is wearing a Black Rifle Coffee shirt which was Reece's favorite coffee in the books.