PhysicsServer2d collisions help

Godot Version

4.2.1

Question

Hi all, I was wondering how it’s possible to have the bullets report collision against each other in this example:

godot-demo-projects/2d/bullet_shower at master · godotengine/godot-demo-projects · GitHub.

Ive set the collison mask to 1, and when i debug draw collisions i can see them but i can’t get them to run a callback upon collision.

Ive tried this to no avail: