Spectroscopic and dynamical properties of the Ar-n-HCO+ (n = 1-13) cluster series have been explored by exciting the chromophore HCO+ in the vicinity of its nu(1) C-H stretch transition. Spectra were obtained by mass selecting the clusters, exposing them to tunable, pulsed LR light (0.02 cm(-1) bandwidth), and monitoring the fragment intensity as a function of laser frequency. The yl band of the Ar-HCO+ dimer is rotationally resolved and has a form consistent with a linear proton-bound complex. Analysis in terms of a pseudodiatomic Hamiltonian yields the following parameters : nu(0) = 2815.063 +/- 0.020 cm(-1), B" = 0.06646 +/- 0.000 08 cm(-1), D" = (7 +/- 4) x 10(-8) cm(-1), B’ = 0.06829 +/- 0.000 08 cm(-1), D’ = (17 +/- 4) x 10(-8) cm(-1). The rotational line widths indicate a lifetime of more than 250 ps for the optically prepared state. The nu(1) vibrational bands of the larger Ar-n-HCO+ clusters, while lacking resolved rotational structure, are still reasonably narrow (<10 cm(-1)) and decrease in width as the cluster size increases. Excitation of the yl transition in Ar-n-HCO+ (n = 2-13) results in the production of a relatively narrow range of daughter ions. Incremental Ar binding energies are extracted from the branching ratio data using a statistical model which takes into account the kinetic energy of the departing Ar atoms. The variation with cluster size of the binding energies, vibrational band shifts, and combination band spacings are argued to be evidence for Ar-n-HCO+ structures where A atoms form primary and secondary solvation rings about a linear Ar-HCO+ core with shell completion at n = 12. This view is consistent with simple empirical potential energy calculations.