  The charged-current quasi-elastic scattering of muon neutrinos on calcium and
argon targets is calculated for neutrino energy up to 2.8 GeV. The calculations
are done within the framework of the relativistic distorted-wave impulse
approximation, which was earlier successfully applied to describe
electron-nucleus data. The model is first tested against experimental data for
electron scattering off calcium and then it is applied to calculate
(anti)neutrino cross sections on 40Ca and 40Ar. We show that reduced exclusive
cross sections for neutrino and electron scattering are similar. A significant
nuclear model dependence of both inclusive and total cross sections for energy
about 1 GeV was found. From the comparison of the (anti)neutrino differential
and total cross sections per (proton)neutron, calculated for the carbon,
oxygen, and argon targets it is evident that the cross sections decrease slowly
with the mass-number of the target due to nuclear effects.
