PSO-1
Encyclopedia
Telescopic sight
A telescopic sight, commonly called a scope, is a sighting device that is based on an optical refracting telescope. They are equipped with some form of graphic image pattern mounted in an optically appropriate position in their optical system to give an accurate aiming point...
was at the time of its introduction (around 1964), the most technically advanced telescopic sight ever designed for a mass-production designated marksman or sniper rifle. The PSO-1 telescopic sight is manufactured in Russia by the Novosibirsk instrument-making factory (NPZ Optics State Plant) and is issued with the Russian military Dragunov sniper rifle.
Design details
The PSO-1 was specifically designed for the SVD as a telescopic sight for military designated marksman activities. The current version of the sight is the PSO-1M2. This telescopic sight is different from the original PSO-1 only in that it lacks the now obsolete Infra-Red detector. The metal body of the PSO-1 is made from a magnesium alloy. The PSO-1 features a battery powered red illuminated reticle with light provided by a simple diode bulb. It features professionally ground, fully multi-coated optical elements, a baked enamel finish for scratch protection, and an attached, quick-deployable, extendable sunshade.The scope body is sealed and filled with nitrogen, which prevents fogging of optics and was designed to function within a -50 °C to 50 °C temperature range.
Considered the higher end of Soviet military side mount telescopic sights, the quality of the PSO-1 is higher than most other PSO-style telescopic sights. The PSO-1 has neither a focus adjustment nor a parallax
Parallax
Parallax is a displacement or difference in the apparent position of an object viewed along two different lines of sight, and is measured by the angle or semi-angle of inclination between those two lines. The term is derived from the Greek παράλλαξις , meaning "alteration"...
compensation control. Most modern military tactical scopes with lower power fixed magnification such as the ACOG
Advanced Combat Optical Gunsight
Advanced Combat Optical Gunsights are a series of telescopic sights manufactured by Trijicon. The ACOG is designed to be used on the M16 rifle and M4 carbine, but Trijicon has developed ACOG accessories for certain other firearms...
, C79 optical sight
C79 Optical Sight
The C79 Optical sight is a small arms telescopic sight of 3.4x28 magnification. A tritium illuminated reticle provides for normal and low-light conditions sighting. The sight itself is Nitrogen-purged to prevent fogging and is covered with an armoured coating of rubber...
or SUSAT
SUSAT
The Sight Unit Small Arms, Trilux, or SUSAT, is a 4× telescopic sight with tritium-powered illumination, utilised at dusk or dawn. The full name of the current model is the SUSAT L9A1. The sight is not designed as a sniper sight, but is rather intended to be mounted on a variety of rifles and to...
(intended for rapid close-intermediate range shots rather than long-range sniping) lack such features as well. Modern fixed magnification military high end grade sniper telescopic sights scopes intended for long-range shooting usually offer one or both of these features. The positioning of the scope’s body to the left of the bore’s center line may not be comfortable to all shooters.
Bullet Drop Compensation elevation turret
The PSO-1 elevation turret features bullet drop compensation (BDC) in 50 m or 100 m increments for engaging point and area targets at ranges from 100 m up to 1,000 m. At longer distances the shooter must use the chevrons that would shift the trajectory by 100 m per each chevron. The BDC feature must be tuned at the factory for the particular ballistic trajectory of a particular combination of rifle and cartridge at a predefined air density. Inevitable BDC induced errors will occur if the environmental and meteorological circumstances deviate from the circumstances the BDC was calibrated for. Marksmen can be trained to compensate for these errors.Besides the BDC elevation or vertical adjustment control of the reticle, the windage or horizontal adjustment control of the reticle can also be easily dialed in by the user without having to remove turret caps etc.
Mounting system
Castellated nut
A castellated nut, also called a castle nut or slotted nut, is a nut with slots cut into one end. The name comes from the nut’s resemblance to the crenellated parapet of a medieval castle....
that screws into the bottom of the locking lever. The spring-loaded portion of the clamp has to be pressed down to tighten or loosen the castle nut as needed.
The telescopic sight is factory matched to the rifle by engraving the scope's serial number on to the butt stock of the SVD rifle. Commercial Russian Tigr rifles (based on the SVD military rifle) have the serial number of the rifle engraved in to the PSO-1M2 scope's side mount.
PSO-1 reticle
The picture to the left is a stadiametric rangefinder that can be used to determine the distance from a 1.7 metre tall object/person from 200 m (2) to 1000 m (10). For this the lowest part of the target is lined up on the bottom horizontal line. Where the top of the target touches the top curved line the distance can be determined.
This reticle lay out is also used in several other telescopic sights produced and used by other former Warsaw Pact member states.
The three lower chevrons in the center are used as hold over points for engaging area targets beyond 1,000 meters (the maximum BDC range setting on the elevation drum). The user has to set the elevation turret to 1,000 meters and then apply the chevrons for 1,100, 1,200 or 1,300 meters respectively.
The 10 reticle hashmarks in the horizontal plane can be used to compensate for wind or moving targets and can also be used for additional stadiametric rangefinding purposes, since they are spaced at 1 milliradian
Angular mil
An angular mil, also mil, is a unit of angle. All versions of the angular mil are approximately the same size as a trigonometric milliradian.-History:The milliradian was first identified in the mid nineteenth Century...
intervals, meaning if an object is 5 m wide it will appear 10 hashmarks wide at 500 m.
The reticule can be illuminated by a small battery-powered lamp.
Optical specifications and dimensions
- MagnificationMagnificationMagnification is the process of enlarging something only in appearance, not in physical size. This enlargement is quantified by a calculated number also called "magnification"...
: 4x - ObjectiveObjective (optics)In an optical instrument, the objective is the optical element that gathers light from the object being observed and focuses the light rays to produce a real image. Objectives can be single lenses or mirrors, or combinations of several optical elements. They are used in microscopes, telescopes,...
diameter: 24 mm - Field of viewField of viewThe field of view is the extent of the observable world that is seen at any given moment....
: 6° - Exit pupilExit pupilIn optics, the exit pupil is a virtual aperture in an optical system. Only rays which pass through this virtual aperture can exit the system. The exit pupil is the image of the aperture stop in the optics that follow it. In a telescope or compound microscope, this image is the image of the...
: 6 mm - Eye reliefEye relief-Eye Relief and Exit Pupil:The eye relief of a telescope, a microscope, or binoculars is the distance from the last surface of an eyepiece at which the eye can obtain the full viewing angle. If a viewer's eye is outside this distance, a reduced field of view will be obtained...
: 80 mm - Limiting optical resolutionOptical resolutionOptical resolution describes the ability of an imaging system to resolve detail in the object that is being imaged.An imaging system may have many individual components including a lens and recording and display components...
: 12 SOA - Power supply for reticle illumination: 1 AA batteryAA batteryAn AA battery is a standard size of battery. Batteries of this size are the most commonly used type of in portable electronic devices. An AA battery is composed of a single electrochemical cell...
- Weight 0.6 kg
- Overall dimensions (L x W x H): 375 x 70 x 132 mm
Accessories
The PSO-1 is issued with a lens hood that can be attached to the ocular to reduce/eliminate image quality impairing stray light and a carrying case to protect the sight during transport and storage.Similar telescopic sights
: POSP telescopic sight: Type JJJ telescopic sight: PSO telescopic sight: Type 78 telescopic sight: LPS 4x6° TIP2 telescopic sight made by I.O.R.I.O.R.
IOR is the acronym for the name of Întreprinderea Optică Română . It is a major optics company established in 1936 in Bucharest, Romania. I.O.R. produces military and civilian grade optics for export and domestic production. Famous for its own version of the Russian PSO-1 type scopes , binoculars...
: PSO 4x24M, PSO 6x24M, PSO 6x42, PSO 8x42, PSO 8x42D, PSO 4-8x42D, 1P21 (PO 3-9x42M): ZRAK M-76 4x 5°10’ / ZRAK ON-M76 telescopic sight