My Great Grandfather died a few days ago, and I was wondering how I could find his military records from WW2?

I think he was Army, I don't know if he saw combat. He's never talked about it, so I think he did. I knew he was a veteran, a lot of my family are, I never asked about it because I was always told it was extremely rude.

I'm hesitant to spend money on any sites like Ancestry or similiar because I doubt they have his military records and not just information that I already know about him, and I don't want to file a request with the LoC that could possibly take years to get back to me.

Is there any way I could get any information in a relatively quick fashion and if I'm paying know I'm getting what I want?