This article presents a formalized conceptual model for a portion of the Field Artillery (FA) domain. The structural part of the model identifies the entities in the FA domain along with their properties and associations. The behavioral part of the model describes the FA missions in the language of Live Sequence Charts (LSCs). The conceptual model is constructed as a metamodel by using the GME (Generic Modeling Environment) toolkit. Once the FA metamodel is loaded, GME automatically provides a customized environment to model particular FA missions. The intended application is to use the FA metamodel as the source for defining model transformations targeting FA federation architectures. This work is also intended to help evaluate the power and limitations of chart notations for describing military tasks visually yet precisely.