Abstract: Provided is an open sight addition for a telescopic gun sight of a type having a front bell which includes a cylindrical forward portion and a frustoconical rearward portion. A sight bead is mounted on an upper central portion of the cylindrical forward portion of the bell. The sight beat projects vertically upwardly from the bell. An elongated sight line is formed on an upper central portion of the frustoconical rearward portion of the bell, rearwardly of and in axial alignment with the sight beam on the forward cylindrical portion of the bell. The sight bead and the sight line together form a sight plane.

Abstract: A two-part mounting ring (58) mounts a rear sight element (100, 114) of an open gun sight on a rear portion of a telescopic gun sight (10). A forward two-part mounting ring (32) mounts a forward open sight element (28) on a forward portion of the telescopic gun sight (10). The upper portion of the rear mounting ring (58) includes a vertical slideway (74). The rear sight element (100, 114) has a slide body (76, 106) located within the slideway (74) which is adjustable up and down along the slideway (74). A sight line carrying element (98, 112) is secured to the slide body (76, 106). The sight line carrying element (90) may be pivotally attached (94) to the slide body (76), for pivotal movement about a horizontal axis (94), between an upright in use position and an inactive position down close against the telescopic gun sight (FIG. 2). The front mounting ring (32) has an upper major portion (34) and a lower minor portion (36).