To address the challenges of excessive free recoil energy and difficult buffering/braking during ultra-high kinetic energy artillery launches, this study draws inspiration from carrier-based aircraft arresting cable technology. We constructed an artillery free-recoil arresting buffer system and designed an experimental test platform. A multi-body system dynamics model was developed for the arresting cable buffering and braking process during free recoil. Experimental and simulation data comparisons validated the model: the maximum absolute relative error at characteristic points did not exceed 7%, confirming the accuracy of the dynamics model. The system successfully meets the testing requirements for buffering and braking for free recoil in new ultra-high kinetic energy artillery. Based on the validated model, we further proposed an arresting cable configuration scheme achieving a braking distance of less than 10 m. This method provides an effective engineering solution for buffering and braking applications involving free recoil energies below 20 MJ.