Yes, all guns need to be registered with the Provost Marshal and this can be done at the Motor Vehicle registration (open only weekdays, I think 8-4 or so). It takes about a week to get the paperwork back.

If the Privately Owned Range (Range 1) is open, you can shoot with a DoD card. To open the range, all you need is a range safety card. You can get one by attending a safety course on Saturday at Range Control (I think it's usually held at 1 pm). All you need is one person with a yellow Range Safety card and another DoD card holder to open the range.