Abstract: The bore sighting apparatus or alignment device is comprised of a two-part ring hinged together and provided with a clamp for securing the ring on the muzzle of a howitzer. A pair of hinged witness sights are provided on the ring and a pair of arms extend outwardly from opposite sides of the ring. A vertical arm is hinged on the outer end of each arm with a target and leveling vile being disposed at the top of each vertical arm. A turnbuckle-type device is connected between the upper end of each vertical arm and the horizontal arm for adjusting the vertical arm to a true vertical position. The targets are comprised of a cylinder having a pattern in glass on the viewing end with the opposite end having a smaller opening with a translucent lens to allow the entry of light to illuminate the viewing end. The targets may be sealed and filled with nitrogen to eliminate fogging and a fitting is provided on the rear of the target to accept a collimator lighting source for night bore sighting.

Abstract: A symbol plate for an artillery collimator and an artillery gun sight has a vertical center line across the plate and symbols arranged in a row symmetrically in relation to the center line. The symbols are formed of digits which are arranged to indicate numeral values proportionally variable with the distance to the center line, the digits being arranged with opposite inclination on opposite sides of the center line.

Abstract: A low reflectance reticle immersed in optical cement between transparent strates. A copper reticle is vacuum deposited upon one transparent substrate and chemically treated to produce anti-reflectance properties. The reticle and substrate to which it is attached are then cemented with optical cement to a second transparent substrate to immerse the anti-reflectance reticle between tranparent substrates in optical cement. The immersed reticle thus formed has superior anti-reflection properties and is protected from mechanical damage by its immersed location. Immersed reticles may be installed between elements of a compound lens if desired.

Abstract: This invention relates to a reticle for riflescopes and the like having crossed filaments defining the aiming reference, the center sections of such wires being flattened in a direction parallel to the viewing axis.

Abstract: A method of producing an optical reticle and the reticle produced thereby. thin layer of aluminum is deposited on the face of a sapphire substrate and a reticle pattern is chemically etched therein. The system is then exposed to air at an elevated temperature for approximately one hour to oxidize the remaining aluminum layer. A film of titanium is next placed over the rough aluminum oxide as by sputtering, for example, and the excess titanium is etched away by the same pattern to produce the finished reticle.