  Point-contact tunneling on CaC$_6$ crystals reproducibly reveals
superconducting gaps, $\Delta$, of 2.3$\pm$0.2 meV which are $\sim$~40% larger
than earlier reports. That puts CaC$_6$ into the class of very strong-coupled
superconductors since 2$\Delta$/kT$_c\sim$~4.6. Thus soft Ca phonons will be
primarily involved in the superconductivity, a conclusion that explains the
large Ca isotope effect found recently for CaC$_6$. Consistency among
superconductor-insulator-normal metal (SIN), SIS and Andreev reflection (SN)
junctions reinforces the intrinsic nature of this result.
