Types of bows

While there is great variety in the construction details of bows (both historic and modern) all bows consist of a string attached to elastic limbs that store mechanical energy imparted by the user drawing the string. Bows may be broadly split into two categories: those drawn by pulling the string directly and those that use a mechanism to pull the string.

Directly drawn bows may be further divided based upon differences in the method of limb construction, notable examples being self bows, laminated bows and composite bows. Bows can also be classified by the bow shape of the limbs when unstrung; in contrast to simple straight bows, a recurve bow has tips that curve away from the archer when the bow is unstrung. The cross-section of the limb also varies; the classic longbow is a tall bow with narrow limbs that are D-shaped in cross section, and the flat bow has flat wide limbs that are approximately rectangular in cross-section.

A compound bow is a bow designed to reduce the force required to hold the string at full draw, allowing the archer more time to aim. Most compound designs use cams or elliptical wheels on the ends of the limbs to achieve this. A typical let-off is anywhere from 65%–75% – for example, a 60-pound compound bow will only require 15–20 pounds of force to hold at full draw.

The unique Penobscot bows or double-bows of Wabenaki region (New England and the Canadian Maritimes) are sometimes suggested to be an ancient compound bow. They involved a small bow attached to the back of a larger main bow. This combination results in both substantially increased draw weight for a relatively small main bow, useful for hunting the moose and caribou of the region, and the ability to adjust the draw weight by tensioning the small bow.

Mechanically drawn bows typically have a stock or other mounting, such as the crossbow. They are not limited by the strength of a single archer, and larger varieties have been used as siege engines.

Bows made of Green wood (undried), are mainly used in survival situations to provide food for the survivor. Green wood bows are usually and made the best out of Pine. Draw weights are usually 25 pounds and below, only made for hunting small game such as rabbits, birds, and fish.

Types of arrows and fletching

The most common form of arrow consists of a shaft with an arrowhead attached to the front end and with fletching and a nock attached to the other end. Shafts are typically composed of solid wood, fiberglass, aluminum alloy, carbon fiber, or composite materials. Wooden arrows are prone to warping. Fiberglass arrows are brittle, but can be produced to uniform specifications easily. Aluminum shafts were a very popular high-performance choice in the latter half of the 20th century due to their straightness, lighter weight, and subsequently higher speed and flatter trajectories. Carbon fiber arrows became popular in the 1990s and are very light, flying even faster and flatter than aluminum arrows. Today, arrows made up of composite materials are the most popular tournament arrows at Olympic Events, especially the Easton X10 and A/C/E.

The arrowhead is the primary functional component of the arrow. Some arrows may simply use a sharpened tip of the solid shaft, but it is far more common for separate arrowheads to be made, usually from metal, stone, or other hard materials. The most commonly used forms are target points, field points, and broad heads, although there are also other types, such as bodkin, judo, and blunt heads.

Shield cut straight fletching – here the hen feathers are barred red

Fletching is traditionally made from bird feathers, but also solid plastic vanes and thin sheet like spin vanes are used. They are attached near the nock (rear) end of the arrow with thin double sided tape, glue, or, traditionally, sinew. Three fletches is the most common configuration in all cultures, though more may be used. When three-fletched fletches are equally spaced around the shaft with one placed such that it is perpendicular to the bow when nocked on the string (though with modern equipment, variations are seen especially when using the modern spin vanes). This fletch is called the "index fletch" or "cock feather" (also known as "the odd vane out" or "the nocking vane") and the others are sometimes called the "hen feathers". Commonly, the cock feather is of a different color, traditionally the hens are solid and the cock is barred. However, if archers are using fletching made of feather or similar material they may use same color vanes, as different dyes can give varying stiffness to vanes, resulting in less precision. Also, like-colored fletching and nocks can assist in learning instinctive shooting (i.e. without sights), a technique often preferred by "traditional" archers (shooters of longbows and recurves). When four-fletched often two opposing fletches are cock-feathers and occasionally fletches are not evenly spaced.

The fletching may be either parabolic (short feathers in a smooth parabolic curve) or shield (generally shaped like one-half of a narrow shield) cut and is often attached at an angle, known as helical fletching, to introduce a stabilizing spin to the arrow while in flight. Whether helical or straight fletched, when natural fletching (bird feathers) are used it is critical that all feathers come from the same side of the bird. Oversized fletching can be used to accentuate drag and thus limit the range of the arrow significantly; these arrows are called flu-flu’s. Misplacement of fletching can often change the arrow's flight path dramatically.

Bow string

Dacron and other modern materials offer high strength for their weight and are used on most modern bows. Linen and other traditional materials are still used on traditional bows. Almost any fiber can be made into a bow string. The author of "Arab Archery" suggests the hide of a young, emaciated camel. Njál's saga describes the refusal of a wife, Hallgerður, to cut her hair in order to make an emergency bowstring for her husband, Gunnar Hámundarson, who is then killed.

Protective equipment

Finger tab

 Most archers wear a bracer (also known as an arm-guard) to protect the inside of the bow arm and prevent clothing from catching the bow string. The Navajo people have developed highly-ornamented bracers as non-functional items of adornment. Some archers also wear protection on their chests, called chest guards or plastrons. Roger Ascham mentions one archer, presumably with an unusual shooting style, who wore a leather guard for his face.

The drawing fingers, or thumb in the case of archers using the thumb or Mongolian draw, are normally protected by a leather tab, glove, or thumb ring. A simple tab of leather is commonly used, as is a skeleton glove. Medieval Europeans probably used a complete leather glove.

Eurasia tic archers using the Mongolian draw protected their thumbs, usually with leather according to the author of "Arab Archery", but also with special rings of various hard materials. Many surviving Turkish and Chinese examples are works of considerable art; some are so highly ornamented that they could not have been used to lose an arrow. Presumably these were items of personal adornment. In traditional Japanese archery a special glove is used, provided with a ridge which is used to draw the string.

Release aids

Archers using compound bows usually use a release aid to hold the string steadily and release it precisely. This attaches to the bowstring at the nocking point and permits the archer to release the string by pulling a trigger. The "trigger" may be an actual trigger lever which is depressed by a finger or thumb (or held then released) but it may also be some other mechanism. Hydraulic and mechanical time delay triggers have been used, as have "back tension" triggers which are operated by either a change in the position of the release or "true back tension"; that is to say the release triggers when a pre-determined draw weight is reached. A mechanical release aid permits a single point of contact on the string instead of three fingers. This allows less deformity in the string at full draw, as well as providing a more consistent release than can be achieved by human fingers.

Shooting technique and form

The bow is held in the hand opposite to the archer's dominant eye, though holding the bow in the dominant hand side is advocated by some. This hand is referred to as the bow hand and its arm the bow arm. The opposite hand is called the drawing hand or string hand. Terms such as bow shoulder or string elbow follow the same convention. Right-eye-dominant archers hold the bow with their left hand, have their left side facing the target, sight towards the target with their right eye and handle the arrow and string with their right hand.

Modern international competitive form

To shoot an arrow, an archer first assumes the correct stance. The body should be perpendicular to the target and the shooting line, with the feet placed shoulder-width apart. As an archer progresses from beginner to a more advanced level an 'open stance' is used/developed. Each archer will have a particular preference but mostly this term indicates that the leg furthest from the shooting line will be a half to a whole foot-length in front of the other, on the ground.

To load, the bow is pointed toward the ground and the shaft of the arrow is placed on an arrow rest which is attached in the bow window. The back of the arrow is attached to the bowstring with the 'nock' (a small plastic component which is typified by a 'v' groove for this purpose). This is called nocking the arrow. As said above, typical arrows with three vanes should be oriented such that a single vane is pointing away from the bow.

The bowstring and arrow are held with three fingers. When using a sight, the index finger is placed above the arrow and the next two fingers below. The string is usually placed in either the first or second joint of the fingers.

The bow is then raised and drawn. This is often one fluid motion which tends to vary from archer to archer. The string hand is drawn towards the face, where it should rest lightly at an anchor point. This point is consistent from shot to shot and is usually at the corner of the mouth or on the chin. The bow arm is held outwards toward the target. The elbow of this arm should be rotated so that the inner elbow is parallel to the ground though Archers with hyper extendable elbows tend to angle the inner elbow toward the ground as exemplified by the Korean archer Jang Yong Ho.

In proper form, the archer stands erect, forming a 'T'. The archer's lower trapezoid muscles are used to pull the arrow to the anchor point. Some bows will be equipped with a mechanical device, called a clicker, which produces a clicking sound when the archer reaches the correct draw length.

The arrow is typically released by relaxing the fingers of the drawing hand (see Bow draw). Usually this type of release aims to keep the drawing arm rigid and move it back using the back muscles, as opposed to using arm motion. An archer should also pay attention to the recoil or follow through of his or her body, as it may indicate problems with form (technique).

Aiming methods

There are two main forms of aiming in archery: using the sight picture or not.

The sight picture includes the target and the bow, as seen at the same time by the archer. With a fixed "anchor point" (where the string is brought to, or close to, the face), and a fully extended bow arm, successive shots taken with the sight picture in the same position will fall on the same point. This allows the archer to adjust aim with successive shots in order to achieve a good standard of accuracy. It cannot be used with short bows, which by definition do not allow a full draw. Modern archery equipment usually includes sights which mark the predicted impact point. Sight picture aiming is universally used with modern equipment and also by many archers who use traditional bows. It allows good accuracy to be achieved after a moderate amount of practice.

When using short bows, or shooting from horseback, it is difficult to use the sight picture. The archer may look at the target but without including the weapon in the field of accurate view. Aiming involves the same sort of coordination between vision and motion that is used when throwing. With sufficient practice, such archers can normally achieve good practical accuracy for hunting or for war. Aiming without a sight picture may allow more rapid shooting.

Instinctive shooting is a term often used, but there is no agreed definition. Some use it to mean shooting with a sight picture but without giving it conscious attention. Others use it to mean shooting without a sight picture.

Physics

Bows function by converting elastic potential energy stored in the limbs into kinetic energy of the arrow. In this process, some energy is dissipated through elastic hysteresis, reducing the overall amount released when the bow is shot. Of the energy remaining, some is damped both by the limbs of bow and the bowstring. Depending on the elasticity of the arrows, some of the energy is also absorbed by compressing the arrow, causing it to "bow out" to one side. This results in an in-flight oscillation of the arrow in which its center protrudes out to one side and then the other repeatedly, gradually damping down as the arrow's flight proceeds; this can be clearly seen in high-speed photography of an arrow at discharge. Modern arrows are made to a specified 'spine' (stiffness) rating which is matched to the power of the bow in order to ensure that the arc of the oscillating arrow carries the rear of the shaft clear of the bow; any contact after the arrow is loosed risks deviating the arrow from the point of aim.

The straight flight of an arrow is dependent on its fletching. The arrow's manufacturer can arrange fletching to cause the arrow to rotate along its axis if desired. This improves accuracy by evening pressure buildups that would otherwise cause the arrow to slowly tilt in a random direction after shooting. If the fletching is not arranged to induce rotation, it will still improve accuracy by causing a restoring torque any time the arrow tilts away from its vector of travel.

Arrows themselves may be designed to spread or concentrate force, depending on their applications. Practice arrows, for instance, use a blunt tip that spreads the force over a wider area to reduce the risk of injury. Arrows designed to pierce armor in the middle ages would use a very narrow and sharp tip to concentrate the force. Arrows used for hunting would use a narrow tip that broadens further down the shaft to facilitate both penetration and a large wound.