Abstract: A flat gun spring for hand guns in which a rib is formed in the spring extending from the butt end of the spring toward the claw end. The longitudinal dimension of the rib extends a major portion of the spring. The depth of the rib progressively decreases from the butt end of the spring to the claw end of the spring. The progressively decreasing depth of the spring permits more energy to the stored in the spring during the early stages of hammer rotation and less energy in the later stages of hammer rotation. This eliminates "stack up" immediately prior to hammer release. The region of the spring closest to the claw end is arcuate and the width of the spring tapers from the butt end to the claw end. These factors further reduce stack up. The spring is formed with substantially constant thickness, and the rib is formed with substantially constant width.