One method for generating pulsed, supersonic liquid jets is by projectile impact, often referred to as the 'Bowden-Brunton" method. In this article, the fundamental processes by which such jets are generated are investigated. The momentum transfer from the projectile to the liquid and the shock wave reflection within the nozzle cavity are the key items of interest. In this study, a new one-dimensional analysis has been used in order to simplify this complex and difficult problem. First, the impact pressure obtained from the projectile is derived. Then, an investigation of the intermittent pressure increase in both a closed end cavity and a simple stepped, cross-sectional nozzle cavity (sac) is carried out. The nozzle pressure and final jet velocity are estimated and compared with experimental results, with which they show good agreement, and to a previous analytical method Also, experimental shadowgraph visualization of the jet penetrating the air is presented. Some interesting characteristics, such as a rippled leading edge main (bow) shock wave in the air and the appearance of a second shock wave, can be seen. These characteristics relate well to those anticipated by the analysis.