Military surplus is now handled by govliquidation.com. I grew up as an Air Force brat, and was used to seeing guys in uniform everywhere on base. The last few times I've been on base was to pick up surplus, and I didn't see a single U.S. uniform. The guards at the gate were from a private security firm & everyone at the surplus warehouse & yard were all civilians. If the military wants to get rid of something, they hand it over to govliquidation on base & they auction it off. You can get everything from tool boxes, skis, generators, mills, blasting cabinets, reloading brass, treadmills and even small ships & airplane frames. Yes, sometimes the lots are big, that's because they have a minimum bid of $150. They don't want to become ebay selling off each nut & bolt separately for $0.27.
Just to clarify, this is a DIRECT CHANNEL ON BASE to purchase surplus from the U.S. military. This isn't some Army Navy surplus store selling stinky uniforms & gas masks, Govliquidation is ON BASE, run by a private company getting rid of whatever the military wants to unload. You have to go through gate security, drive across the base and pick up the items in a military warehouse run by this company.
My favorite site for other government auctions is publicsurplus.com. I buy stuff from school districts, cities & counties. I've got good deals on tools, industrial sewing machines, surplussed library books industrial kitchen supplies, etc.