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Arrows, What do you really know about yours?
By Troy Basso*

After literally years of bowhunting and attending archery events I finally decided to become more of a self-sustainer with my archery gear. I figure I had paid the Pro-Shop owners mortgage payment for several years now in just arrow work. The proverbial "fly in the buttermilk" was I had depended on my pro-shop for everything over the years. After much consideration I decided to leave the actual bow repairs to the professionals. I was going to handle everything else myself. I was going to start with the arrows but, what did I really know about arrows? I found out real fast I wasn't as smart as I initially believed.

If you walk into any good pro shop you will find a myriad of arrows to choose from. After you get past the space age coatings and material worthy of a shuttle mission there are really just three basic types of arrow shafts. The first, oldest, and most traditional is wood, this is primarily used for traditional bows, recurves and childrens bows. Second, and most widely used, is aluminum. The aluminum shaft has been the choice of many bowhunters since the 1940's when Doug Easton started producing them. Last are the carbons or carbon composite shafts.

Regardless of what the shaft is made of they all have the same basic components.

Starting at the string end of the arrow you have the nock, this is the device used to hold the arrow on the string. Some nocks are glued directly onto the end of the shaft, some slide directly into the shaft while others use an insert. The insert is an aluminum or graphite adapter that is glued into the shaft, the nock then fits in the insert. Nocks that slide into the shaft or insert are much more user friendly since you can turn the nock to get the perfect clearance for your fletchings.

Next are the fletchings. They are the "wings", if you will, that help keep the arrow stable in flight. These also come in two basic materials. First and more traditional are feathers.

Second and most popular are synthetic vanes. Feathers, although they are a little faster at closer ranges since they lay down on the shaft when shot, are also more sensitive to moisture. There are several products available to waterproof feathers that really work quite well. Vanes, though generally a little slower, are a more durable choice. Also vanes are much cheaper than their counter part feathers. They both come in different lengths but 4 inch seems to be the most versatile for the bow hunter. If you are planning on using a large cut on impact broadhead and a light shaft you may want to consider 5" feathers or vanes.

Next on the business end of the shaft will be either an insert, glued into the shaft, or an outsert, glued over the shaft. The outserts are larger and have lost popularity because they tend to be hard to remove from a target. The insert/outsert is where you screw in your field point or broadhead. The inserts are generally "shaft specific" meaning a 2314 shaft requires a 2314 insert.

When choosing your arrows the most important consideration would be the spine of the arrow. Spine is the term used to describe the stiffness, or resistance to bending, of the shaft. The exact size you need will depend on three factors. First is your draw weight and second is your Arrow length and third the type of cam . It is best to consult a Pro-Shop or visit www.easton.com for a chart to get you in the ballpark as to which shaft will be best for your set up. The numbers on the actual shaft tells you a lot about its spine. Every arrow manufacturer has its own set of numbers so I will stay with a standard Easton aluminum shaft. Take a 2413 shaft; the first two numbers (24) are the shaft's diameter in 64ths of an inch. The second two numbers (13) are the actual wall thickness of the shaft in thousandths of an inch. So a 2413 has a larger diameter than a 2117 but it has a thinner wall.

Now you're wondering about the choice between carbon and aluminum. The best thing about a carbon arrow is that it's either straight or broken, no worries about bent arrow shafts. Carbon is also lighter so therefore faster. The increase in speed equals a flatter trajectory over a longer distance. The down side to all of this is the loss of weight does gain you speed but in turn it reduces the "punch" or kinetic energy. The recommended minimum arrow weight for most hunting applications is, six grains of arrow weight per pound of your draw weight. To find the kinetic energy for your set up you need your arrow speed or velocity, and your arrow weight in grains. The formula is velocity x velocity x arrow weight in grains divided by 450,240.

Arrow Penetration

Bring up arrow penetration in deer camp this year and you're going to probably get an earful of opinions about the subject. This is probably one of the most over debated and least understood aspects of bowhunting. In reality though, given today's modern archery tackle it's not really a concern for the average bow hunter. The age-old arguments about which broadhead or arrows penetrate better are generally pure speculation or one person's perception based on their personal experience.

There are four crucial factors in determining the penetration of a specific set up. They are broadhead type or style, arrow flight, friction and last but not least is Kinetic Energy.

Broadhead type

Any discussion about which broadhead is the best is likely to become a generally heated conversation. Today's bow hunter has so many styles of broadhead to choose from it can be hard to figure out what you want. There are really three basic styles of broadhead. The cut on impact styles like the steel force or Magnus heads, the chisel point heads like a muzzy, and the expandable family of heads. When shooting various styles into a foam block the traditional cut to tip head penetrated deeper than the popular chisel point three-blade head. Now granted, the difference in the three is just exactly how much farther one sticks in the ground than the other after making a good shot. All three styles of broadhead work equally well on deer sized game IF you practice good shot placement. The popular expandable heads penetrated the least in the foam block in comparison to the fixed blade or cut on impact designs. Yet every year literally thousands of deer are taken using them. The one concern with these heads is not only are they illegal for hunting in some select state's but there are a few western outfitters who won't allow their clients to use them.

Arrow Flight

Arrow flight can effect your penetration in a big way. If you're getting perfect arrow flight all the stored energy in the arrow is placed directly behind the broadhead thus assisting the penetration. If your arrow is sliding tail left or right you may hit where you aim but you're not getting the maximum energy stored in the shaft. Perfect arrow flight is especially important when shooting a mechanical broadhead.

Friction

Friction is the drag on a particular arrow/broadhead set up during penetration. A larger diameter Easton 2413 will have more "drag" or friction than an ACC 3-49 will because the ACC is so much smaller in diameter. Broadhead design will also increase or decrease friction. A traditional style head with a cut to tip point will have less friction than a chisel point as the chisel point will have to blow through the hide or rib before the blades can cut. The difference is minimal at best. On the expandable heads there is even more friction as the chisel point must bust through, then the blades must open before you can reduce friction by letting the sharp blades do their job.

Kinetic Energy

Kinetic Energy (or KE) is the single most important factor that effects arrow penetration. To calculate your KE you must first know your arrow speed in feet per second, this is your velocity, and your arrow weight in grains. The formula is Velocity X Velocity X Arrow weight divided by 450,240. Since the boom of carbon arrows with their faster and more durable characteristics kinetic energy has become even more important. A carbon shaft is in fact lighter and faster but the loss of weight can in certain set-ups have an effect on your kinetic energy. Take for instance an aluminum shaft that weighs 499 grains. If this arrow is traveling at 270 FPS it will generates 80.79 foot-pounds of KE or kinetic energy. A carbon shaft of the same length shot out of the same bow will weigh around 396 grains and travel 285 FPS. This arrow generates 64.44 pounds of kinetic energy. On the surface it looks dramatic but in reality Easton recommends 24-41 foot Pounds of KE for deer sized game, 42-65 for elk, black bear and wild boar. You can draw your own conclusion about KE. The only area of concern is the use of carbon shafts with expandable heads. Generally speaking most mechanical heads need at least 50 lbs of KE to function properly as a tremendous amount of your KE is used to open the blades.

The bottom line is, a modern bow, arrow and broadhead in the hands of a competent bowhunter will take most deer sized game with total pass thru shoots. The real key is shot placement. Bowhunters must have very intimate knowledge of their prey's anatomy in order to know just where to place the shot for a clean, quick harvest. If you are not sure on shot placement consider taking the National Bowhunter's Education Course as they offer many aids for the archer pertaining to shot placement. By only taking those high percentage shots an archer should have no problems. One last thought is that your equipment, no matter the cost, is only as good as you are thus practice is actually more important than upgrading or replacing your bow. Also, no amount of kinetic energy, speed or draw weight can ever make up for a poor shot or an accidental hit on a major bone.

*Troy Basso is a freelance writer and instructor for the National Bowhunter Education Program.

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