This study reports experimental density and sound velocity data of 1-chloroheptane and 1-iodoheptane at 291.45 <= T <= 413.15 K and 1 <= P <= 1961 bar along with the atmospheric pressure liquid densities at 223.15 <= T <= 423.10 K, sound velocities at 216.08 <= T <= 413.15 K, and isobaric heat capacities at 223.15 <= T <= 423.15 K. The evaluated values of the auxiliary thermodynamic properties are provided as well. An analysis performed in this study is based on the entire available high-pressure database of the medium chain 1-alkyl halides. It is demonstrated that, within its applicability range, the fluctuation theory based Tait-like equation of state (FT-EOS) predicts the high-pressure experimental data in a particularly accurate manner. The performance of the critical point based perturbed chain statistical association fluid theory (CP-PC-SAFT) is dependent on the robustness of the T-c and P-c data, whose appropriate values allow reliable predictions of densities until extremely high pressures, sound velocities, heat capacities, and the available binary high-pressure phase equilibria data. The entirely predictive CP-PC-SAFT + MYS (modified Yarranton-Satyro correlation) modeling framework yields reliable viscosity estimations of 1-alkyl chlorides and their mixtures. At the same time, it accurately predicts the pressure dependence established by the viscosity of 1-bromobutane only up to similar to 2000 bar and it tends to underestimate this property for 1-iodoalkanes. Investigation of trends established by CP-PC-SAFT allows making some essential assumptions about the regularities characteristic for thermophysical properties of 1-alkyl halides at elevated pressures.