A mockery of "hardcore" defined as a member of the National Guard (typically, though not necessarily a Guard Bum) who has served six years or more without a combat deployment, avoids deployments, or always seems to end up with cushy missions to Europe, the Baltic, or Central America. A Guard-Core Soldier or Airman is usually seen decked-out in more gear than necessary, is typically overly enthusiastic given his/her limited experiences, and frequently incorporates recruiting paraphernalia into his/her daily civilian wardrobe.
"Sergeant X is pretty Guard-Core considering he is overweight, has made a twenty year career out of the Guard and his only time spent overseas was that two-week trip to Latvia. Where does he get all those National Guard polo shirts? Why hasn't he gone to Iraq like the rest of the National Guard?"