Reverse Engineering Camtastic file to PCB in Altium
After working with this for over a year I've found a couple ways of achieving this.

First, working with DXF files is superior. I usually can import those directly into the pcb editor. If I can't, I import them into the cam editor, then export them to another DXF file, then import them into the pcb editor.

If I only have Cam files, The one thing I missed was this



Within Tables > NC tools  I needed to specify a drill size. Often times that fixed my problem.