  We report on studies of Classical Nova (CN) explosions where we follow the
evolution of thermonuclear runaways (TNRs) on Carbon Oxygen (CO) white dwarfs
(WDs). We vary both the mass of the WD (from 0.6 M$_\odot$ to 1.35 M$_\odot$)
and the composition of the accreted material. Our simulations are guided by the
results of multi-dimensional studies of TNRs in WDs that find sufficient mixing
with WD core material occurs after the TNR is well underway, reaching levels of
enrichment that agree with observations of CN ejecta abundances. We use NOVA
(our 1-dimensional hydrodynamic code) to accrete solar matter until the TNR is
ongoing and then switch to a mixed composition (either 25% WD material and 75%
solar or 50% WD material and 50% solar). Because the amount of accreted
material is inversely proportional to the initial $^{12}$C abundance, by first
accreting solar matter the amount of material taking part in the outburst is
larger than in those simulations where we assume a mixed composition from the
beginning. Our results show large enrichments of $^7$Be in the ejected gases
implying that CO CNe may be responsible for a significant fraction ($\sim$ 100
M$_\odot$) of the $^7$Li in the galaxy ($\sim$1000 M$_\odot$). In addition,
although the ejected gases are enriched in WD material, the WDs in these
simulations eject less material than they accrete. We predict that the WD is
growing in mass as a consequence of the accretion-outburst-accretion cycle and
CO CNe may be an important channel of Supernova Ia progenitors.
