EspressoFiend wrote:It is a Gaggia Classic with a Rancilio Rocky.
The Gaggia Classic has an over-pressure valve (opv) which opens to redirect any excess pressure from the pump back to the reservoir. From what I recall, these OPVs are set to 11-12 bar from the factory, as 11 bar is what the E.S.E. standard for pods are, as I recall.
Given that your machine vents excess pressure back to the water tank, I would say no, pulling daily ristrettos won't hurt your machine, as it's designed to deal with the excess pressure generated by the pump. If your machine did not have an OPV, there may be the potential for damage, but as far as my experience and expertise go, that is mere speculation.