Tā suīrán shì gè lǎobīng, dàn cóng bù xuànyào zìjǐ de jīnglì.
Although he's a veteran, he never boasts about his experiences.
Tips
usage
老兵 can mean both a currently serving experienced soldier (vs. 新兵 xīnbīng, new recruit) and a retired military veteran. Context makes it clear. The more formal term for 'veteran' (retired) is 退伍军人 (tuìwǔ jūnrén).