Bradley Cooper & Sienna Miller Get All Prepped for a Day of Filming 'American Sniper'

Bradley Cooper emerges from his trailer while prepping to get to work on American Sniper on Thursday (May 15) in Los Angeles.

The 39-year-old actor was joined on set that day by his co-star Sienna Miller, who wore a pregnant baby belly on set, and director Clint Eastwood.

American Sniper centers on a Navy SEAL who recounts his military career, which includes more than 150 confirmed kills. Look out for the film to hit theaters in 2015.

20+ pictures inside of Bradley Cooper and Sienna Miller emerging from their trailers to prep for filming…