Raise boring is a widely used method for drilling shafts in mining and civil engineering projects. Maintaining wall stability and safety during back reaming remains challenging. Increasingly, there is a requirement for shafts, raises and orepasses to be excavated deeper where increasing stresses may present stability issues. Stress induced overbreak complicates raise excavation impacting safety, schedule, and lifespan. A thorough geotechnical investigation remains the starting point in understanding the geotechnical risks to raise bore projects. Empirical raise boring stability assessments are widely used in the industry and form the starting point in shaft investigations. These methods have been enhanced by the addition of raise bore performance data in recent years due to the improvement in post excavation scanning technologies. In this study, the authors have back analysed the stability of several raise bored shafts that have experienced overbreak and added to previously published raise bore design charts. The methodology integrates geotechnical review of the initial assessment parameters and in situ conditions, material properties and the post excavation performance of the raise bored shaft. Scans of raise bore walls have been used to compare the measured depth of failure to the widely used empirical relationship developed by Martin, Kaiser and McCreath (1999). This data has been used to increase the understanding of different rock masses during and after raise boring excavation and adds to the confidence in assessment of reliability (probability of failure/success) of raise bored shafts.