A method for manufacturing a magnetic write head for perpendicular magnetic recording. The method provides for accurate definition of a device feature such as a write pole flare point. A functional lapping guide is formed to determine when a lapping operation should be terminated to define an air bearing surface of a slider. In order to provide accurate compensation for manufacturing variations in the functional lapping guide, a dummy lapping guide is provided. An amount of variation of a front edge of the dummy lapping guide, which is defined by the same process step as a writer pole flare point, can be calculated by measuring the width (stripe height) of the dummy lapping guide based on its electrical resistance. Since the back edges of the dummy lapping guide and functional lapping guide are defined by the same manufacturing steps, the back edge of the functional lapping guide can then be determined, and used for accurately control of the writer flare point through their correlation established from the dummy lapping guide.