The UK Marginal Initiation Characterisation Test (MICT) has been developed to cover two areas of research: as an initial screening test for candidate energetic materials; and as a technique for characterising the effects of composition changes, ageing and temperature on detonation spreading performance. Tests have been undertaken on UF‐TATB, UF‐TATB/HMX and a highly loaded HMX PBX. The initiation system has been tuned to deliver a suitable pressure/time profile to marginally initiate each of these compositions. Subsequently, a study of sensitivity and divergence as a function of charge attributes (e.g. composition and density) has been completed. In addition, first stage hydrocode modelling of the MIC Test has been completed using CTH. The modelling output has highlighted the relationship between the prominent features in the results and the confinement around the explosive sample.