Resize a collision box to match size of mesh in BP?

I have a parent BP with x amount of children. The children are various items of variou sizes. I want a specific collision box around the mesh in the children. I added a collision box to the parent and nested it under the mesh and they all have it. Good.

Now on event begin play I want the collision box to resize so its just slightly larger than the mesh. Mesh could be an apple or it could be a golf club etc.

Any Ideas on how to do this? I tried getting the mesh transform and setting the box to same with no affect. I also tried the same with scale3d.

Thanks!