See the screw at the lower rear of the action body? This is the fulcrum of the original design Anson & Deeley sear. It is in the bottom of the action body and engages a detent in the tumbler from below, close to the tumbler fulcrum. During the 1920s the Suhl gunmakers almost universally adopted E.Kerner's modification of the A&D lockwork. Kerner relocated the sears to the top/rear of the action. They turn on a screw located at the top rear of the action and engage a detent on the top of the tumblers, removed as far as possible from the hammer fulcrum. This arrangement vastly improved the leverage. As much less mainspring pressure rested on the sear detent, Kerner's top sears allow lighter and at the same time safer trigger releases. Secondary safety sears are unnecessary with Kerner's sear arrangement.
