Using the Show Collision console command will show collision for existing actors, but if a new actor is spawned its collision is not shown. This is problematic when trying to visually debug projectile collision.
As a test, fire a projectile into the air and quickly pause the game, then enter the console command. The collision will be displayed. Fire another projectile, and the new projectile will not have its collision displayed.
1. Launch: UE4Editor.exe
2. Create a new First Person Blueprint template project
3. PIE
4. Enter the console command, "show collision"
5. Fire a projectile
Result:
The projectile actor does not display its collision sphere
Head over to the existing Questions & Answers thread and let us know what's up.