Collision Event lacks Skeletal Mesh's BoneName

I’ve got a projectile that collides with characters. Even though the colliding component is definitely the skeletal mesh component, the bone name in the hit result is always “none”.

I have overridden Projectile::NotifyHit(…). Do I have to override another function to get valid bone names? Or do I need to set some variables I don’t know about on projectile or character-mesh??

When I do a line trace, the bone name is provided in the hit result, why not here?