An object of the design of a concentric recoil bearing is to insure reliable full-film lubrication over as much of the recoil and counter recoil motions as possible. The surface profile has a great effect on the oil film produced in the bearing. A straight bearing profile produces only a thin and unreliable film. A small taper on the leading edge greatly improves the situation. However, a shallow blind slot in the loaded sector of the bearing was the best surface profile of those studied. Although the slot war less than a mil deep, it resulted in a faster acting bearing and an appreciable thicker oil film. At the highest bearing pressure, the 10 millisecond film thickness was almost twice that of the next best profile studied. This design holds great promise, not only for concentric recoil bearings, but also for bearings for reciprocating shafts where the bearings must be fast-acting and where they support large loads.Presented as an American Society of Lubrication Engineers paper at the ASLE/ASME Lubrication Conference held in Miami Beach, Florida, October 21–23, 1975