Just to clarify what Audioguru said:
LM317 will work with 240 ohms so long as the total output current is 10mA or more. In fact, it will work with values even higher than 240 ohms, but the output voltage is equal to
(Vref/Rref+Iadj)*Rset + Vref, where Rset is the resistor from Adj to GND,
so if you make Rref too high, Iadj will be significant and make the output voltage less predictable.
If you expect to get the correct output voltage with no load, then, as Audioguru says, you should use 120 ohms or less.