bobthebanana:
Hmm, they did work when I first tested them after noticing the problem. And I was pulling 500 mA from all of them. Now 2 of them give 6v when set to 5v and one gives 4.8v. I can only pull, guess how much, 7 mA now. Do they usually die this quick or did I get fakes? Who knows. I guess I'll include some in the next Digikey order.
I don't think anyone would go to the trouble to sell 'fake' LM317s, but some might sell you 'rejects' from someone's production run. I once ordered ten 3.3volt regulators 78L33 from a seller in Thailand. Everyone one of them worked but not one of them had an output voltage between 3.1 to 3.7, all were at, below or above those values, as if they were out of tolerance rejects from someone's production run.
Lefty