Laser diode M140 current driver
Assuming you are using a TO220 package for your LM317, your pinout is wrong. 

1 - Vadj

2 - Vout

3 - Vin

Also, just as a bit of friendly advice, running an amp through most pots is a bad idea. The wipers will not handle it in the long run. The failure mode will be an open circuit at the wiper, which in your circuit will produce as much current as the LM317 can produce. In this case, that is not enormously more than you want, so you may be alright, but it's still not a good idea.