An experimental investigation of the effect of fuel-to-oxidant ratio and reactant composition on the performance of a lab-scale gaseous rocket engine was performed. The senior design project involved the design, fabrication, and testing of a laboratory scale gaseous reactant rocket engine. A simplified zeroth order combustion model was developed to provide guidance for the design of the rocket system. Conservation equations along with chemical equilibrium results were the fabric of the model development. Peak chamber pressures as a function of reactant delivery rates and nozzle diameters were the primary output of the code. Experiments were conducted as a function of chamber pressure and equivalence ratio. For an equivalence ratio of 1, CH4 mass flow of 1.26 g/s and oxygen flow rate of 4.48 g/s, the measured chamber pressure was nearly 160 psig having a combustion efficiency of 85%. Theoretical pressure-time profiles were compared to empirically-obtained profiles and the peak pressures agreed well. Combustion efficiencies across a broad range of equivalence ratios were found to be approximately 80%±6.