I know several people who followed a non-traditional path to Delta. You'll have stories to tell in the interview. Your mil background can only help...not hurt.
At this point, there are only a few things you can do to make yourself more competitive. Do something more for your company than just fly the line...LCA, training dept., special projects, union work helping your pilot brothers out. Work on a Master's degree (if it's within reach) and make darn sure you get a high GPA.
Your application can't look just like everyone else's in the stack and expect to get the call. More than any other airline, Delta values personal achievement, leadership and customer service. Hours are just the pre-reqs...what else have you done with your time?