It's been a couple years since the USMC stopped using these. What we're seeing now is similar to the HMMWV tires that are everywhere. The military is getting rid of their excess as they convert over to the new 385/85R16's. Same height but wider tires, same ones the Canooks use on their version of the LAV.
There used to be lots of them on eBay all the time but lately they've gotten scarcer. Kicking myself for not buying a set a while back when you could find 10 sets at a time on eBay. Just need one good set with a spare and by the time those wear out we should have a place with a bigger garage and it's time for a lift and those 325's.
If you run across anymore gimme a heads up.