You are going to need 2 forms of ID..
Primary ID must be your VA Driver's license or Personal Identification Card (since you are a VA resident).
Secondary ID has to be an "official" form of ID: this can be a current/valid hunting/fishing license, current bank check, current utility bill, current vehicle/boat registration, valid voter ID card, copy of a current lease agreement, etc.
These forms of ID must have your current residential address on it. If both forms have a PO Box address on them, then you will need something from list 2, with an actuall mailing/911 address on it.
Since you are a VA resident, the fact that you are on active duty assignment doesn't really matter (although, we thank you for your duty).
When/if you were to use your old DL info and second ID, you could be committing a criminal offense when you complete and sign the paperwork (unless, you just moved w/in 30 days).
Best choice of actions: Go to DMV the day you get back and change your driver's license and vehicle registration address to your actual place of residence in the state. This can be a barracks address on base, if that is the case.
Make sure that you ask for a new ID, not just the change of address card to be mailed to you. Your new DL will then have a "REI" code on it, indicating it is a reissue and not a new DL. That way, DMV knows you have lived in the state for over 90 days and you won't have to wait 30 days as a "non-resident just moving into the state.
This will enable you to go to your local dealer and purchase whatever you want. (Except assault rifles, which need a form of ID that proves citizenship).
I think I have been pretty thorough...but if I missed something, shoot me an email and ask. Since I have sold firearms for about 10 years, I like to think I am about 95% correct on current rules/regs...but I have been wrong once or twice!
NSTG8R