When someone talks almost endlessly about their past military experiences, including historical facts, anecdotes and tales of buffoonery. It is possible to be caught in a conversation with a group of sandbaggers, this can be a dangerously boring situation, difficult to get away from and should be avoided by civilians at all costs.
Tony: "Tim, did I ever tell you about the Naval Commander that invented the jubilee clip?"
Tim: "What the f**k has that got to do with anything? Don't start sandbagging!"