Computational modeling is routinely used to design protective systems such as blast containment chambers. Hydrocodes are used to define the loads produced if the explosive items were to detonate and finite element analysis codes to calculate the response of the chamber. These efforts typically assume the explosive is a spherical charge. This article investigates the effect this assumption has on the blast loads and the calculated response of the chamber. First, simulations benchmarking a hydrocode with adaptive meshing and Jones–Wilkins–Lee equation of state are performed. How various aspects of the scenario affect the loading on the vessel is discussed. The code is next used to calculate the loading from a spherical charge and one representative of a configuration typically found in actual use of storage vessels. The more realistic charge configuration is found to produce higher loads on the vessel walls. The structural response of the chamber to both charge configurations is calculated using finite element analysis. The non-ideal configuration is found to produce a very different response than the typically assumed ideal spherical charge.