Components of a Bow
A bow consists of two elastic limb ends, traditionally made from wood, connected by a string. By pulling the string backwards, the archer exerts compressive force on the string facing section, or back. The stored energy is later released by putting an arrow into flight.
The curved limbs may have a single curve, such as a longbow, or ends that bend back upon themselves as in a recurve bow.
Bowstrings can be made from sinew, animal intestines, plant fibers such as linen or hemp, or modern polymer cordage.
How to construct a bow from a tree limb
You can easily construct a suitable short-term bow. When it loses its spring or breaks, you can simply replace it.
Finding suitable wood for a bow
Find a piece of wood about five feet long and about 1 1/2 to 2 inches thick. A limb or sapling works great. Select a hardwood stick that is free of knots or limbs. Dead, dry wood (but not gray and cracking) is preferable to green wood. Good bow wood includes lemon tree, oak, hickory, yew, ash, or teak. Juniper and mulberry work well too as they are flexible. If you must use green wood, pine wood is a good option.
How to determine the belly side of the bow wood
To find the natural belly of a piece of wood, stand the piece upright with one end poking into the ground. Place one hand loosely over the top. With the other hand, push the middle of the stave. It will swivel, indicating which way the wood is naturally curved. The outside (facing away from you) is called the back while the inside is the belly.
Shaping the bow
When shaping the bow, you will leave the outside (back) untouched, only scraping away the inside, belly material. You may also want to leave a 6-inch section in the center untouched. You can use this section for a handhold.
Placing one end of the stave into the ground and holding the other with your hand, push the middle to bend the bow. Notice which areas have natural bends and which areas do not. Using a knife (or rock if in a survival situation), scrape away wood from the belly where the wood does not bend. Leave material in the areas that have a natural bend.
Always scrape from the side that faces you, the inside curve or belly of the bow. Leave the back side untouched. Otherwise, the bow will break the first time you pull it. The objective is to create a bow with limbs that bend evenly throughout the length of the bow.
Continue scraping/slicing off material while frequently checking the bend of the limbs. The bow should be thicker, and hence stronger with less bend, in the center. Similarly, the ends of the limbs (tips) should remain straight with little bend. When completed, the bow should have a thick center flanked by two thinner, and more flexible, end segments that are roughly the same thickness and length as each other.
Creating a bend in the bow wood
To create a bend in the wood, you can soak the wood in hot water to soften it. After bending, smoke it over a fire to dry it and set its shape.
Creating the bow notch
Cut notches about 1-2 inches from each end. The notches should be the shape of a half-moon on the outside of the bow’s curve. Attach the tips of the bows with cordage and only use a bowstring on one bow.
You can also carve a small notch in the center of the bow giving an area to set the arrow into. This will help keep the arrow from wobbling while aiming.
Tillering the bow as a final adjustment
Finally, use a branch about head-high to hold the bow for the next step – tillering. Put the middle of the bow on the branch so that the bow is held horizontally. Pull downward on the string and observe how the limbs bend. Make final adjustments to the bend by scraping away wood (on the belly side) where the wood is less bendable. The objective is for each limb to bend the same amount so that when bent, they look like mirror images of each other.
Observe which limb bends less and carefully remove more materials from the belly of that limb until both limbs bend equally and evenly. Re-check frequently, pulling down on the string a little bit further each time until you can pull it to your draw length. The tillering process is complete once both limbs flex equally and evenly and the draw weight (pounds of pressure required to pull the string back to a full draw) is at your desired poundage.
Increasing the pull of the bow
To increase the pull, lash a second bow to the first, front to front, forming an “X” when viewed from the side. You can also wrap wet leather around the center to further strengthen the bow. Ancient Chinese bow makers also glued layers of animal bone and animal tendons/ligaments to add strength.
Finishing the surface of the bow to preserve it
The bow can be finished by sanding the belly and oiling it with linseed or tung oil (melted fat can be used in a wilderness survival situation). Tiller it as needed.
Making arrows in the wild
Select arrows from the straightest dry sticks available. Light woods such as wood, bamboo, goldenrod, mullen, or reed work well. The arrows should be about half as long as the bow.
Scrape each shaft smoothly all around. You will probably have to straighten the shaft. You can bend an arrow straight by heating the shaft over hot coals. Do not allow the shaft to scorch or burn. Hold the shaft straight until it cools.
You must notch the ends of the arrows for the bowstring. Cut or file the notch; do not split it.
Fletching (adding feathers to the notched end of an arrow) improves the arrow’s flight characteristics. Fletching is recommended but not necessary on a field-expedient arrow. Feathers work well. You can glue the feathers to the base of the arrow shaft or split the back of the arrow, slide the feather in, and lash with thin thread.
Check here for more details on arrow-making in the wild.
Making Arrow Points in the wild
To make an arrow point, use the same procedures for making a stone knife blade. Chert, flint, and shell-type stones are best for arrow points. You can fashion bone like stone—by flaking. You can make arrowheads from bone, glass, metal, or pieces of rock. You can also sharpen and fire-harden the end of the shaft. To fire-harden wood, hold it over hot coals or plunge it deep under the coals in the ashes, being careful not to burn or scorch the wood. The purpose of fire hardening is to harden the wood by drying the moisture out of it.
Using a Bow and Arrow
While it may be simple to make a bow and arrow, it is not easy to use one. You must practice using it for a long time to be sure that you will hit your target. Also, a field-expedient bow will not last very long before you must make a new one. For the time and effort involved, you may well decide to use another type of field-expedient weapon.
To shoot a bow and arrow, first point the arrow towards the ground and place the shaft of the arrow on the arrow rest (the notch that you carved in the middle of the bow). Slip the arrow end onto the bow string. Use three fingers to hold the arrow on the string. Typically, the index finger is held above the arrow and the middle and ring fingers held below the arrow. Raise your arm. Hold the bow arm outwards toward the target. The inner elbow should be parallel to the ground and the bow should always stay vertical. Draw the string towards your face, typically towards your chin or corner of the mouth (be consistent in how you draw the bow). Release the arrow by relaxing the fingers of your string hand.