Just because you are not technically in academia when you are in the service doesn’t mean you aren’t learning enough to earn college credit.
The G.I. Bill is one thing, but let’s face it: you have skills. It seems unfair for you not to get college credit in, say, engineering for your practical study if you act as an engineer for your military occupational specialty (MOS). Yet many schools simply don’t acknowledge equivalent credit from what may be hands-on work in higher stress situations than any other kind of freshman has ever faced.