Gene Hackman

While many actors felt proud to serve their country, Gene Hackman wasn’t too excited about joining the U.S. Marines back in the 1960s. You see, at that time, Hackman’s father had abandoned the family; afterward, his mother struggled to raise the family on her own. Desperate for a fresh start, Hackman ultimately lied about his age to become a U.S Marine.
Afterward, the Marines transferred Hackman overseas to China, where he served as a radio operator. Later on, they relocated him again, this time to Hawaii. While enlisted, Hackman received demotions three times since he had trouble negotiating with discipline and power. But hey, all that confrontation probably gave him some serious performing chops.
James Garner

Long before James Garner entered the acting world, he served in the military. Back in 1944, Garner applied to the U.S. Merchant Marines in the hopes of making some extra money. Unfortunately, Garner later discovered that he suffered from severe seasickness, which is something that made it rather difficult to fulfill his duties.
Ultimately, he enlisted with the California Army National Guard, where he joined the 5th Regimental Combat Team as a shooter. Afterward, Garner spent fourteen months in Korea during the Korean War. While he was injured twice, he was lucky enough to survive. Even though he never managed to become a sailor, the U.S Army awarded him many medals, including the Purple Heart.