Sights: Iron Sights: Open Type Sights

In our previous post, we studied some basics about iron sights. Now we will study one of the types of iron sights, the Open sight.

In an open type sight, the rear sight is merely a piece with a notch cut in the middle. The notch is typically V-shaped, square shaped or U-shaped. The front sight is usually some kind of ramp or post.

The above picture is an example of an open-type sight. It is typically made of steel or polymer. Note the rear sight is merely a small piece with a square notch in the center. The front sight is a small post type. In the above example, the front sight is fixed to the barrel, but the rear sight may be slid left or right using proper tools, to adjust the horizontal alignment of the sight. In the above example, the rear sight also has a white line surrounding the notch, to give it greater contrast from the surroundings, to make it easier to aim.

In some cases, the front and rear sights also have small dots of some material that glows in the dark (e.g.) glass tubes filled with tritium gas. This helps in picking up the sights in the dark as well.

Since tritium is a radioactive form of hydrogen, it slowly decays and emits light as it does so. Therefore, sights like these don't need any batteries and could easily last 10 years or more. These sights are much more visible in low light conditions.

These sights are characterized by their simplicity of design. There is not much that can go wrong with them. They are also small and unobtrusive, so they don't affect the balance of the pistol much at all. They also can't get caught easily on clothing or holsters because of their small size and shape. Hard blows may bend or move the sights out of alignment though, but on the whole they are pretty durable. Rain, fog and snow don't affect these sights much at all. These sights are cheap to manufacture and don't use batteries or electronics, so there is less to go wrong.

These sights are not as precise as other sights though. Square shaped notch on the rear sight provides the best accuracy of different open iron sight types. Other types are not as precise and also take longer to aim. Peering through the sights also obscures other details which are covered up by the sides of the sights.

Sights like these are pretty useful up to about 300 meters or so, though most average shooters can shoot them typically to 100 meters or so. These are therefore typically used by shorter range weapons such as civilian shotguns, police revolvers and pistols etc.

One famous assault rifle that was originally designed with open type sights is the AK-47. The rear sight is an adjustable one with a simple V-shaped notch cut on it, while the front sight is a post. The rear sight may be slid forwards and backwards to adjust for range. One may now purchase AK clones with other types of sights as well, but the original version was designed with open-type sights, which is typical for this simple, reliable weapon.

Sights: Iron Sights

In our previous post, we learned a bunch of basics about sights in general. The first type of sights we will study are called Iron Sights. The name itself is a bit of a misnomer these days, as this type of sight is rarely made of iron in modern times. Steel or polymer plastic are usually the materials of choice these days. However, in the early days of firearms, these were indeed made of iron and the name is a historical one.

So what is an iron sight? It consists of two pieces, the front sight, which is fastened towards the front of the barrel (muzzle) and the rear sight, which is fastened near the back of the barrel (the breech). These pieces may be fixed or adjustable to accommodate for range and windage. Aiming is done by using the human eye alone. There is no device for magnification (such as a telescope) or low light conditions (night vision device), just the two pieces. The user simply lines these two pieces onto the target and then pulls the trigger. The two pieces for most iron sights are in the shape of a bead, a post or a ring, or combinations of each (e.g. front sight may be a post and rear sight may be a ring, or both sights may be posts etc.)

There are two main categories of iron sights: (a) the open type and (b) the aperture type. We will study more about these types of sights in the following posts.

Iron sights are usually characterized by the following features:

• Simplicity: There is very little that can go wrong with iron sights, as they are very low tech indeed, compared to some other types of sights. They are mostly immune to recoil effects. Since iron sights don't have any electronics or batteries, there is less that can go wrong with them.
• Weather resistance: Iron sights are usually pretty sturdy and are not much affected by the effects of weather and temperature.
• Ease of training: These are pretty basic sights and it doesn't take a brain surgeon to figure out how to use them.
• Durability: Most sights are pretty resistant to shock, unlike other types such as telescopic sights. Since iron sights are usually smaller and low-profile, they are usually less likely to get knocked out of alignment when handling the gun. However, hard blows can sometimes knock even iron sights out of alignment.
• Less weight: Iron sights are very light and do not affect the balance of the gun much. This is unlike other types of sights, that may be much more bulky.
• Cheap: Since they are so low-tech, they are also very cheap to manufacture.

There are also some disadvantages with using iron sights:

• Lower precision: Not as precise as some other sight types and also difficult to adjust accurately.
• Lower range: Since there is no image magnification with iron sights, the aiming is based on how good the user's eyesight is.
• Reduced field of view: The front and rear sights will block out some of the surroundings when the user lines them up with the target, especially the lower half of the target.