An analysis of the thrust versus combustion time curve has been carried out from the static test results of a rocket motor with a small-size solid propellant (K-round). It was conducted by observing the similarity of the shape of the test result’s curve, the area under the curve, the slope of the line of sudden pressure increase, and the appearance at the beginning of the sudden pressure increase. As a comparison, the curve from the results of the static test of a rocket motor with a homogeneous propellant mixture is presented using a standardized process. From the analysis, we obtained that the rocket motor with the homogeneous propellant mixture of the same propellant composition did not give similar static test curve shapes, thus yielding a different area under the curve due to the Isp value difference. We also found that the slopes of the sudden pressure rise line are not the same, although the appearance at the beginning of the sudden rise is similar. The value (occurrence) of the start of the sudden rise is suspected to be related to the initial igniter, not to the propellant.