Jake, interestingly the Scan Atlanta page doesn't list Ft.Gordon, however, that shouldn't be taken as no one knowing anything.
In addition to the Milcom group on qth.net (heck, it might even be listed in Grove's freq directory), and the Georgia forum here on RR, there are 2 - maybe more - very active Yahoo scanning groups for the state. Sometimes the best sources are the local ones...
The C-130's are probably from the 700th Airlift Squadron at Dobbins ARB. The Preston Drop Zone at Ft Gordon is a favorite destination of theirs. Try 239.975, 252.2, and 379.525 for their air-air. Their callsign is COBB.
Fort Gordon is located on the northern edge of the very active Bulldog MOA which is used primarily by F-16's from the 20th Fighter Wing at Shaw AFB and F/A-18's from VMFA-142 at NAS Atlanta. You will occasionally hear F/A-18's from MCAS Beaufort as well. The common discrete for the MOA is 343.75. The Atlanta Center entry/exit frequency for the MOA is 323.0. Search the 138-144 MHz and 148-150 MHz ranges in AM mode whenever you hear activity on 343.75 and you will find the F-16's air-air. VMFA-142 (callsign GATOR) will use 328.55, 344.4, and 345.05 for air-air.
You can also try all of the frequencies for Bush Field (http://www.airnav.com/airport/KAGS) which is the emergency divert field for the aircraft operating in the Bulldog MOA. The C-130's also like to use it quite a bit.
If you hear what sounds like digital CCs in the 380-400 mhz area, you've found one of the new P25 Trunk systems that are slowly evolving nationwide in this band. If it' s running unencrypted then the 396 and 996 can trunktrack them. The other digital-capable trunktrackers will be able to listen in conventional mode, but not track them.
If it's encrypted, like they say on the Sopranos, fuggedabodit (forget about it, for those that don't speak NJese, hi) 73s Mike