Abstract: An elongated resilient retainer is positioned between an excavating tooth and tooth holder such that the tooth and tooth holder compress and, thus, deform the retainer to frictionally secure the tooth to the tooth holder. The resilient retainer includes ribs that extend longitudinally along its outer surface. These ribs are circumferentially spaced such that when the retainer is under compression, the ribs engage and grip the upper and lower edges of the tooth adjacent thereto. In this way, the area of surface contact between the resilient retainer and the surface between which it is compressed is augmented to more securely hold the tooth in the tooth holder.

Abstract: An adjustable sighting means for a firearm which a shooter can adjust to give the desired point of impact. An elongated rib is adjustably mounted on the gun barrel. The rib can be adjusted in the vertical direction so that the forward end of the rib has a greater vertical movement than the rear end of the rib. The effective pivot point of the rib is to the rear of the rib at a theoretical point which remains constant and is selected to be the position of an average shooter's eye when in shooting position.