According to an article on the EBF website (Europeanbowhunting.org), a website dedicated to informing people about the effectiveness of bow hunting for game conservation, North American bow hunters bagged over one million whitetails, blacktails and mule deer in 2011. The article went on to say that bow hunters in the US have increased by as much as 10% in the last ten years with a total of over 3 million in 2011. Whether you are looking to join the ranks of bow hunters to provide for your family, bond with friends and family, or just enjoy the outdoors you may have some questions about selecting a bow for your hunting needs. This article won’t compare different brand name bows, but will give you a basic knowledge of the most commonly used bows, a brief comparison of those bows, and a brief explanation of a bows power.
Types of Bows
While choices such as crossbows, the newest addition to “bow” hunting, and longbows are available these are not as common as the two primary categories and will not be discussed in this article. The most common used bows for hunting fall into two categories: recurves and compounds.
Recurve bows are simple in design. Traditional recurves come as a single piece of layered wood, fiberglass or other material. Modern recurves have two interchangeable limbs, or ends, connected to the body known as the riser. Both traditional and modern limbs are bent outward at their ends. When the string is properly attached it will lay flat against these curved ends.
Compound bows are much more complex in design. They also have limbs and a riser, but unlike a recurve the string does not directly touch the limbs. Instead the string is suspended between the limbs on a system of wheels, called cams, which are connected to the limbs.
All bows operate on the same principle to fire an arrow. When a bow is drawn it stores the energy required to force the arrow forward. Once the string is released the stored energy is converted to the arrow. The amount of conversion will be different for both recurves and compounds because of their design. It is the conversion of stored energy that is the major difference in recurves and compounds.
The simplistic design of the recurve uses the bows natural resistance to create and store energy. The limbs resist against the drawing of the string and store the energy that will be converted to the arrow. The hunter must apply an equal force to overcome the bows resistance, this is known as draw weight (measured in pounds (lbs)). Once the bow has been fully drawn the hunter must hold this draw weight as he prepares his shot. Upon release of the string the limbs return to their natural state transferring the stored energy through the string to the arrow. The amount of energy that is transferred to the arrow is determined by the bows material and their natural recoil. Increased draw length can increase the amount of stored energy, but bow will only transfer the additional energy proportionally with its natural recoil. Increasing your draw length, however, will also increase the draw weight making it more difficult to hold the bow at full draw. While this may seem to be a disadvantage of recurves it can easily be overcome with some physical conditioning.
One of the advantages compound bows have is found in its cams. The cams reduce the draw weight required to hold the bow while the hunter prepares his shot, this is known as “let off.” Let off is the percent of draw weight that is reduced when the bow is held at full draw. A 50 lb. draw weight on a bow with a 65% let off (typical of most cams today), reduces the draw weight to only 17.5 lbs. Because of the reduced draw weight this generally leads to longer hold times and better quality shots.
Unlike recurves the complex design of compound bows relies primarily on the cams to convert the stored energy rather than the bows material makeup. When a compound bow is drawn the cams, rather than the limbs, store the energy. The cams are shaped to more efficiently convert the stored energy which results in greater conversion rates and generally provides more power and an increased range over recurves.
A bows power is measured in foot/pounds (ft/lbs). The misconception for a number of years was that a greater draw weight equated to a more powerful bow, i.e. a 70 lb. bow was more powerful than a 40 lb. bow. While draw weight plays a critical role in power more in depth studies have determined that arrows mass and speed (discussed in a separate article) plays an equally important role. Therefore increasing draw weight will not always relate to an equal increase in power. When selecting a bow, hunters should focus on purchasing a bow with a maximum draw weight that is comfortable to draw in order to maintain consistency in shooting habits.
While there is not a nationally recognized requirement for bow power, hunters will want to ensure their bow has sufficient power for their hunting needs. Most hunters will agree that 45 ft/lbs. are sufficient for hunting whitetail deer, but recommend at least 55 ft/lbs. for larger game. When determining if your bow is meeting these recommendations your local archery dealer should have a chronograph and scale and to tell you if your bow has enough power for your hunt.
Regardless of why you have chosen to join the ranks of bow hunters, knowing the two primary types of bows used and understanding the basic mechanics of each will help you make an educated decision in selecting your bow. Knowing a bow’s power is not solely dependent on the draw weight will prevent you from purchasing a heavier bow than necessary as long as it has sufficient power.
Happy hunting and good luck.