We present preliminary results on the analysis of very deep echelle UVES (8m VLT) spectra of the Galactic H II region S311 (NGC 2467) located outside the Solar circle. The data cover from 3100 to 10450 Å with a resolution R ~ 8800. We have detected and measured more than 300 emission lines, some of them are faint recombination lines of heavy-element ions. We have derived the O abundances from OI and OII recombination lines and the C abundance from CII lines and an Ionization Correction Factor (ICF). This kind of observations will permit us to derive the Galactic abundance gradient of C and O from nebular recombination lines, which are almost independent on the real temperature structure of the nebula.