  We consider the possibility that neutrinoless double beta decay may occur in
models with unbroken lepton number via the emission of a massive gauge boson
with electron lepton number $-2$. We determine the shape of the $\beta\,\beta$
sum energy spectrum as a function of the gauge coupling, independent of
model-specific details. We discuss our results in light of the persistent
experimental claims that excess events are observed near but below the spectrum
endpoint of several elements.
