Looking down the iron sight of an M15A4 Carbine (a civilian copy of the M4 carbine)

The term iron sights refers to the open, unmagnified aiming system used to assist the aiming of a variety of devices, usually those intended to launch projectiles, such as firearms, airguns, and crossbows; they are also used on many telescopes to help point the telescope at a desired target. Iron sights usually consist of some form of notch or apeture in the rear sight and a post, bead or ring in the front sight. Often, the rear sight is adjustable for windage and/or elevation, though in many military rifles, the front sight is also adjustable. Image File history File links Rear_iron_sight_m15a4carbine. ... Image File history File links Rear_iron_sight_m15a4carbine. ... Caliber: 5. ... A projectile is any object sent through the air by the application of some force. ... A firearm is a kinetic energy weapon that fires either a single or multiple projectiles propelled at high velocity by the gases produced by action of the rapid confined burning of a propellant. ... Air guns are weapons that propel a bullet using compressed air or another gas, possibly liquefied. ... A crossbow is a weapon that fires projectiles called crossbow bolts or quarrels. ... 50 cm refracting telescope at Nice Observatory. ... Windage is a force created on an object by friction when there is relative movement between air and the object. ... Basic Definition In geography, the elevation of a geographic location is its height above mean sea level (or some other fixed point). ...

This article will concentrate on firearms sights; the principles described are equally applicable to any device which needs aiming. For the sake of brevity, the term gun will be used to indicate any device aimed by iron sights, the term shooter will be used for the operator of said device, and the term target will be the object at which the device is being aimed.

How iron sights work

Iron sights work by providing horizontal and vertical reference points that allow the shooter to align the gun parallel to the shooter's line of sight. Once the sights are aligned with each other, they are placed in correct relation to the target. This places the gun at a precise angle to the line of sight to the target. With appropriate compensation for range to the target, parallax between the iron sights and the gun's bore, and the trajectory of the projectile, a shot fired will hit the target. When viewing a scene, as in optics, photography, or even hunting, the line of sight is the straight line between the observer and the target. ... Parallax (Greek: παραλλαγή (parallagé) = alteration) is the change of angular position of two stationary points relative to each other as seen by an observer, due to the motion of said observer. ... A trajectory is an imagined trace of positions followed by an object moving through space. ...

A sight picture with focus on the front sight; the gray dot represents the target

Since the eye is only capable of focusing on one plane, and the rear sight, front sight, and target are all in separate planes, only one of those three planes can be in focus. Which plane is in focus depends on the type of sight, and one of the challenges to a shooter is to keep the focus on the correct plane to allow for best sight alignment. A tiny error in sight alignment can be multiplied hundreds or thousands of times by the time the projectile reaches the target; for example, with an Olympic-class air rifle shooter trying to hit a bullseye 1 mm in diameter, with a 4.5 mm diamter pellet at 10 meters, an error of 0.2 mm in sight alignment can mean a miss. Image File history File links Fuzzy_sight_picture. ... Image File history File links Fuzzy_sight_picture. ... Olympic can refer to: The Olympic Games, an international multi-sport event International Olympic Committee (IOC), the organization managing the Olympic Games Various stadiums in the world are known as Olympic Stadium Olympic Airlines, state run airline for Greece and successor to Olympic Airways Olympic Aviation, subsidiary of Greek flag... Air guns are weapons that propel a bullet using compressed air or another gas, possibly liquefied. ... The bullseye is the center of a target (worth 10 points in archery or 50 points in darts), and by extension the name given to any shot that hits the bullseye. ... A pellet is the term for a non-spherical projectile designed to be fired from an air gun. ...

Sights for shotguns used for shooting small, moving targets (wing shooting or clay shooting) work quite differently. The rear sight is completely discarded, and the rear reference point is provided by the correct and consistent positioning of the shooter's head. A brightly colored (generally brass or silver colored, white, or a fluorescent shade) round bead is placed at the end of the barrel. Often this bead will be placed along a raised, flat rib, which is usually ventilated to keep it cool and reduce mirage effects from a hot barrel. Rather than being aimed like a rifle or handgun, the shotgun is pointed — the focus is always on the target, and the unfocused image of the barrel and bead are placed below the target (the amount below depends on whether the target is rising or falling) and slightly ahead of the target if there is lateral movement. This method of aiming is not as precise as that of a front sight/rear sight combination, but it is much faster, and the wide spread of shot allows a hit even if there is some error in aim. Some shotguns also provide a mid-bead, which is a smaller bead located halfway down the rib, which allows more feedback on barrel alignment. A pump-action and two semi-automatic action shotguns and boxes of ammunition A shotgun is a firearm typically used to fire a number of small spherical pellets, the shot, from a smoothbore barrel of relatively large diameter. ... Brass is an alloy of copper and zinc, a solid-solid solution. ... Fluorescence induced by exposure to ultraviolet light in vials containing various sized cadmium selenide (CdSe) quantum dots. ... The barrel of a gun or other firearm is the tube, usually metal, through which a controlled explosion is released in order to propel a projectile out of the end at great speed. ... A road mirage, a type of inferior mirage A mirage, derived from the Latin mirari, meaning to be astonished, is an optical phenomenon which often occurs naturally. ... A shotgun shell is a self-contained cartridge loaded with shot or a slug designed to be fired from a shotgun. ...

Types of iron sights

Iron sights are broken into two basic categories that include most types. Open sights use a notch of some sort as the rear sight, while aperture sights use a circular hole. Wing and clay-shooting shotgun sights are simply called shotgun beads, or simply beads.

Open sights

A selection of open sights, and one aperture sight suitable for use with long eye relief: A) U-notch and post, B) Patridge, C) V-notch and post, D) express, E) U-notch and bead, F) V-notch and bead, G) trapezoid, H) ghost ring]. The gray dot represents the target.

Open sights generally are used where the rear sight is a significant distance from the shooter's eye. They provide minimum occlusion of the shooter's view, but at the expense of precision. Open sights generally use either a square post or a bead on a post for a front sight. The post or bead is placed in the rear sight notch, and the target is placed above and centered on the aligned sights. From the shooter's point of view, there should be a noticable space between each side of the front sight and the edges of the notch; the spaces are called light bars, and the brightness of the light bars provides the shooter feedback as to the alignment of the post in the notch. Vertical alignment is done by lining up the top of the front post with the top of the rear sight, or by placing the bead just above the bottom of the U or V-notch. Image File history File links Download high resolution version (833x153, 2 KB) Summary A collection of drawn sight pictures for various types of open sights, found on pistols and rifles. ... Image File history File links Download high resolution version (833x153, 2 KB) Summary A collection of drawn sight pictures for various types of open sights, found on pistols and rifles. ...

Patridge sights are the most common sights used for target pistol shooting, as most shooters find the vertical alignment is more precise than that of other types of open sight. Express sights are generally considered the fastest of the open sights, as the wide, shallow "V" obscures less of the shooter's vision, and the usually large front bead (similar to a shotgun sight) is easy to find in a hurry. The express sight is the only type of open sight where it is considered acceptable to focus on the target, and not the front sight. In cases where speed far outweighs accuracy (i.e. the shooter is being charged by a Cape Buffalo), then the font sight is used like a shotgun bead; the rear sight is ignored, and the bead is placed below the target. When more time is available, then the focus should be on the bead, which allows more precise placement of the bead in the "V" of the rear sight. A pump-action and two semi-automatic action shotguns and boxes of ammunition A shotgun is a firearm typically used to fire a number of small spherical pellets, the shot, from a smoothbore barrel of relatively large diameter. ... Species Syncerus caffer Subspecies Syncerus is a genus of bovines found in Africa, the only extant member of which is the African Buffalo, or Cape Buffalo. ...

Aperture sights

Aperture sights range from the ghost ring sight, whose thin ring blurs to near invisibilty (hence "ghost"), to target aperture sights that use large disks with pinhole-sized apertures. In general, the thicker the ring, the more precise the sight, and the thinner the ring, the faster the sight. The ghost ring sight is a type of firearm sight consisting of a large front blade and a large diameter, thin rear aperture. ...

A target rear sight with different front sight inserts: A) a ring with horizontal bars, which act as a level reference, B) a ring with a vertical post, C) a simple post, D) a transparent disk with a yellow tint. The gray dot represents the target.

Target aperture sights are designed for maximum precision, and the rear sight is usually a large disk (up to 1 inch or 2.5 cm in diameter) with a small hole in the middle, and placed close to the shooter's eye. The front sight may be a simple bead or post, but is more often a globe type sight, which consists of a cylinder with a threaded cap, which allows a number of differently shaped front sights to be used. Most common are posts of varying widths and heights or rings of varying diameter — these can be chosen by the shooter for the best fit to the target being used. Tinted transparent plastic inserts may also be used, with a hole in the middle; these work the same way as an opaque ring, but provide a less obstructed view of the target. Even for the maximum precision, there should still be a significant area of white visible around the bullseye and between the front and rear sight ring (if a front ring is being used). Since the best key to determining center is the amount of light passing through the apertures, a narrow, dim ring of light can actually be more difficult to work with than a larger, brighter ring. The precise sizes are quite subjective, and depend on both shooter preference and ambient lighting, which is why target rifles come with easily replaceable front sight inserts, and adjustable rear apertures. Image File history File links Target_sight_pictures. ... Image File history File links Target_sight_pictures. ... A right circular cylinder In mathematics, a cylinder is a quadric, i. ... See: transparency (optics) alpha compositing GIF#Transparency transparency (overhead projector) market transparency transparency (telecommunication) transparency (computing) For X11 pseudo-transparency, see pseudo-transparency. ...

Aperture sights on military rifles use a larger aperture with a thinner ring, and generally a simple post front sight. The extreme case of this is the ghost ring sight, a relatively recent innovation that may be the fastest type of iron sight to use, while still providing a degree of precision comparable to or better than most open sights. Ghost ring sights are commonly found on riot and combat shotguns and customized handguns, and they are also gaining ground as a backup sighting system on rifles. A riot shotgun is a shotgun designed or modified for use as a primarily defensive weapon. ... Winchester Model 1897 Pump Shotgun, modified for use in World War 1 Combat shotguns, shotguns modified slightly to increase their suitability for use in combat, have been popular in the United States, both with law enforcement and with the US military (particularly the US Marine Corps), since the 19th Century. ... A handgun is a firearm small enough to be carried and used in one hand. ... A rifle is a firearm that uses a spiral groove cut into the barrel to spin a projectile (usually a bullet), thus improving accuracy and range of the projectile. ...

Shotgun beads

Since shotgun beads are only used by the peripheral vision, generally a larger, brighter bead works best. Fiber optic sights are becoming popular for shotguns, as they greatly increase the brightness of the bead by collecting light and directing it to the shooter's eye. Since the "rear sight" in the case of a shotgun is the shooter's eye position, adjusting the "sights" on a shotgun consists primarily of adjusting the stock to fit the shooter as well as possible. Peripheral vision may be defined is that part of vision that occurs outside the very center of gaze; thus, there is in actuality a very broad set of non-central points in the field of view that may be said to be peripheral. We may speak of far peripheral vision... Fiber Optic strands An optical fiber in American English or fibre in British English is a transparent thin fiber for transmitting light. ...

Iron sight enhancements

While iron sights are basically very simple, that simplicity also leads to a staggering variety of different implementations. In addition to the purely geometric considerations of the front blade and rear notch, there are some factors that need to be considered when choosing a set of iron sights for a particular purpose.

Fixed vs. adjustable sights

All sights are adjustable to some extent; most are dovetailed into the gun, and can be "drifted" back and forth with a hammer and punch. Even in the case of sights that are milled directly into the gun, as are often found on compact revolvers, careful work with a file can change the height of the front or rear sight, and the notch in the rear sight can be widened on one side only to move the center to the side. Diagram of a Dovetail Joint A dovetail joint or simply dovetail is a woodworking technique used to join two pieces of wood at right angles to each other. ... The term mill, when used by itself, can refer to: Mill (factory) - a place of business for making articles of manufacture, e. ...

Since different cartridge loadings (heavier or lighter bullet, higher or lower velocity) will change the trajectory of the bullet, it is common for rifles and many handguns to have adjustable sights. Generally only the rear sight is adjustable, although on graduated sights the rear sight is generally "click"-adjustable, and the front sight adjusts to "zero" the rifle for a given load. Once zeroed, the rear sight can be adjusted in graduated intervals to provide correct point of aim for a variety of distances. These graduated rear sights are generally called "tangent sights" when they are open sights mounted on the barrel, and "tang sights" when they are peep sights mounted behind the receiver. The word cartridge has different meanings, depending on context: Cartridge (electronics) - a module to be inserted into a larger piece of equipment, for example a games cartridge in a games console, or an ink cartridge in a printer. ... Academic procession during the University of Canterbury graduation ceremony. ...

The downside to adjustable sights is the inherent fragility of the moving parts. A fixed sight is a solid piece of metal, usually steel, and if firmly attached to the gun, little is going to be able to damage it beyond usefulness. Adjustable sights, on the other hand, are bulkier, and have parts that must move relative to the gun. A solid impact on an adjustable sight will usually knock it out of adjustment, if not knock it right off the gun. Because of this, guns for self defense or military use either have fixed sights, or sights with "wings" on the sides for protection (such as those on the M4 carbine copy shown above). Self-defense refers to actions taken by a person to defend onself, ones property or ones home. ... Caliber: 5. ...

Iron sights used for hunting guns tend to be a compromise. They will be ajustable, but only with tools--generally either a small screwdriver or an allen wrench. They will be compact and heavily built, and designed to lock securely into position. Target sights, on the other hand, are much bulkier and easier to adjust. They generally have large knobs to control horizontal and vertical movement without tools, and often the are designed to be quickly and easily detachable from the gun so they can be stored separately in their own protective case. A basic screwdriver A screwdriver is a device used to insert and tighten, or to loosen and remove, screws. ... An Allen wrench, Allen key, hex key or hex head wrench is a tool used to drive screws and bolts with a hexagonal socket in the head. ...

Contrast enhancements

Various methods of enhancing the contrast of open sights

While target shooters generally prefer a matte black finish to their sights, to reduce the chance of glare and increase the contrast between the sights and the light bars, black sights don't show up well on dark targets or in low light conditions, such as those often encountered in hunting, military, or self defense situations. This has lead to a variety of different contrast enhanements to the basic Patridge type sight and others. On revolvers, this has generally taken the form of a colored plastic insert in the front sight blade, usually red or orange in color. On semi-automatic handguns, the most common type is a bright white dot painted on the front sight near the top of the blade, and a dot on each side of the rear sight notch. These are called three-dot sights, and when the contrast is too low to use like standard Patridge sights, the front sight dot is centered between the rear sight dots, and the target is placed over the middle dot. Many variations on this exist, such as using a white outline of the rear sight notch, or a single dot below the rear notch, which are lined up to form a figure "8". On military and police guns, the dots are often trasers containing tritium gas and fluorescent material, which emits a dim light due to the radioactive decay of the tritum. Image File history File links Enhanced_contrast_open_sights. ... Image File history File links Enhanced_contrast_open_sights. ... Matte can take on one of at least two distinct meanings. ... Traser is the generic name for glass tubes with a phosphor layer in them and Tritium (a Hydrogen isotope) gas inside the tube. ... Tritium (symbol T or 3H) is a radioactive isotope of hydrogen. ... Fluorescence induced by exposure to ultraviolet light in vials containing various sized cadmium selenide (CdSe) quantum dots. ... Radioactive decay is the set of various processes by which unstable atomic nuclei (nuclides) emit subatomic particles (radiation). ...

Concealed carry sight enhancements

Specific to handguns is the issue of concealed carry. While police and military personnel generally carry their handguns in open holsters that provide easy and unobstructed access, civilians in areas where carry is allowed are usually required to carry their firearms concealed under clothing or some other form of cover, such as a fanny pack or purse. The high contrast, sharp edges that are so popular with target shooters can be dangerous on a concealed firearm--not only can they tear skin and clothing when drawn, but if they become tangled up during the draw, it can have lethal consequenses for the shooter.

The challenge for a designer of sights for a concealable handgun is to pick the right compromise between high visibility and minimum hindrance. Rather than the vertical or even undercut front sights found on target handguns, the front sights of a concealed carry gun will be sloped. The rear sight won't be a vertical plate, but will have depth to provide a gentle slope, and the sight will fit the gun closely, with no gaps or overlaps to snag, or collect dirt and sweat which can cause corrosion.

Sights for use on a concealed handgun also have to consider the potential conditions in which they will be used--probably low light, close range, and with the operator under significant stress due to an imminent threat. Some unusual solutions have been devised, such as the trapezoidal sights (G in the open sight list above) used by Steyr, or the "gutter sight" used by the highly modified ASP S&W model 39. Steyr is a town (population 39,495 as of 2001) in the Austrian federal state of Upper Austria, located on the Enns river. ... Jwissick(t)(c) 03:41, 25 September 2005 (UTC) Categories: Possible copyright violations ...

Other types of sights

For precision applications such as hunting or sniping the iron sights are usually replaced by a telescopic sight, and for target shooting and combat operations low-power magnified or unmagnified optical sights such as red-dot or reflex sights are increasingly common. This article is about the hunting of prey by human society. ... This article is about the military occupation. ... A telescopic sight, commonly referred to as a scope, is a device used to give an accurate point of aim for a firearm. ... A red dot sight is a type of optical aiming device for firearms. ...