Robert Knepper's character Aldrich uses the same single-load gun in this movie as Lance Henriksen's character does in the first Hard Target (1993). It's called a Thompson Center Arms Contender single shot.
The film features doves, a homage to John Woo director of Hard Target (1993). Woo is known for his use of doves in a lot of his films.
Scott Adkins and Jean-Claude Van Damme, the stars of this film and the original Hard Target (1993), were both in The Expendables 2 (2012).
Even though there are numerous characters in this film who are American (or have American accents), Robert Knepper is the only American actor in the film with substantial screen time and multiple uses of dialogue.
At 22 minutes the helicopter's tail number begins with HS which indicates it is registered in Thailand.