Dave , theThe "Disintegration Ray" achievement is awarded when the game detects that the last crew member on an enemy ship was killed by the Anti-Bio Beam, identified by its unique ID. If a modded weapon uses the same ID as the Anti-Bio Beam, the game would consider it as the Anti-Bio Beam and grant the achievement when it kills the final enemy crew member.
So the game decides if you used the Anti-Bio Beam for the Disintegration Ray achievement based on:
- The weapon ID of the Anti-Bio Beam.
- The death of the last enemy crew member by this weapon.