They Have Experienced War
Ernest Borgnine served in the Navy, while Robert Ryan and Clint Walker were both in the Marines during their time in the film. This gives them the upper hand in their roles as they have experienced what it’s like to in an army.
Aldrich Forced Everyone To Get A Haircut
When Aldrich ordered the cast members to change their current haircuts for something more realistic, he wasn’t kidding. While Marvin was happy to oblige with a crew cut, his co-stars were less enthusiastic.