Can Behr primer and paint be used over oil paint?

When a manufacturer claims that their paint is a paint and primer in one, all they are promising is that you can use that paint as the first coat over drywall or a previously painted surface that is clean and in good shape other than a few ordinary repair materials like spackle or putty.

These paints can not normally be used a s bridge between oil and latex paints. For these applications, and any other application other than a simple repaint, a specialty primer should be used.