Arrow Anatomy

A look at the arrow from broadhead to nock

By Jim Burnsworth

My father was a great man. He was always my champion and made me feel very special and important my entire life. He was patient and took his time to make sure he answered all of my thousands of questions about anything and everything. He taught me the importance of words, their meaning, and the effect that they had on people. He was an amazing man in many ways and accomplished great things in his life. He worked on 27 cars that all broke world records, designed and built full-motion videophones, had multiple patents in color corrections and was “man of the decade” in the video industry at one time. One of the many things that I learned from him and apply to my life and success on a daily basis is how to think. I learned this primarily from his example as he worked through so many obstacles that life threw his way. Since I can remember, I’ve always had the need to know and understand how and why things work. This coupled with my “ADHD” has been an interesting combination that I’ve come to realize is one of the blessings in my life. I’ve used my technical understanding and thinking on just about every project that I’ve accomplished in my life.

I remember one Christmas, when I was just shy of 12 years old; my parents got me a bow, and it changed my life. I was hooked and couldn’t put it down. I had to know and understand everything about how and why it worked like it did and how to utilize it to the very best of my ability. My father got a bow for himself so we could learn together. Back in those days, we didn’t have the information available to us that we do today so it was a long hard road to learn as much as we did. Since that Christmas, I have spent the better part of my life shooting, experimenting, and testing myself and my equipment to become a better archer. My dad used to say there is a difference between a gift and a present. A present is something you buy for someone and a gift is well thought out and is made for or has special interest for that person. He never knew how much a bow would influence my life. Thank you dad for everything and for giving me that bow. My father passed away in 2011, but his influence is still with me in everything I do. Life is short; so cherish and embrace your loved ones today.

A few years back I shot a commercial for Limbsaver. They asked if I would fly out and spend some time with one of my all-time hunting heroes, Bob Foulkrod. I used to love watching his videos from “back in the day,” all on VHS of course. When I walked into his shop for the first time I noticed he had every bow he had ever hunted with hung on the wall with the arrows that he had fletched and crested with it. You see, he also wants to know how things work, and he inspired me to go back to my roots and made me aware of the pride we should have in an arrow and that it could be your custom signature in your quiver. The following information is some of what I have learned about arrows, why I shoot what I do, and how to properly tune an arrow to make you a better archer. This stuff might seem a little crazy, but the one thing that I can promise you is that at longer ranges these things will make a difference.

Shafts

My goal when I’m testing and tuning my bow and arrow combination is to get my arrow corrected and in full gyro as quickly as possible. The first thing that I would like to talk about is the two different types of spines that an arrow has. First, there is a spine rating which represents the stiffness of a shaft, representing how the manufacturer measures static spine. The lower the spine rating, the stiffer the shaft. For example, I shoot a 300 spine arrow. This is figured by adding a specified weight to the middle of an arrow that is suspended in the air by both ends. The amount of bend the arrow has, gives it its spine rating. A 300 spine rated arrow, by this measurement, has approximately 3” bend.

Then there is dynamic spine rating. Dynamic spine is based on how the spine reacts when the stored force from the bow is applied. Increasing or decreasing your bow weight changes the dynamics of the spine. There are a million factors and shooting combinations that can affect it, like string weight, point weight, strand count, lengthening or shortening of the shaft, or the insert design, length and weight. If I’m having trouble tuning, I’ll take an arrow that is too long and trim by 1/4” at a time until it tunes correctly. This process is only done after you know the bow itself is tuned correctly.

Now is a good time to talk about the spine alignment of the arrow. Having your arrows spine-aligned is important for increasing your accuracy and taking all that erratic arrow flight out of them. There is a machine designed by FireNock that can find spine in seconds. Some archery pro shops can do this for you for a charge as well.

A couple of year ago I did a feature on my TV show, Western Extreme, where I demonstrated how to find the spine of an arrow at home without any special equipment. I had over 3,000 people write me wanting to understand it better and what it does. It’s simple: first you need to find something that holds water that is longer than your arrow. I’ve found that my bow box does really well. You take the bare shaft and plug both ends so that it will float. I do this by grinding a couple nocks flat so they don’t have wings that would prevent the arrow from spinning in the water. Then go ahead and drop the arrow in the water and it will settle spine up. Mark this spot on every arrow and fletch the nock vane on this mark. Dip the whole dozen and you now have spine-aligned shafts. Make sure that you have cut the arrows to length before finding spine. I have found that when you cut an arrow it can change the spine point by almost 18 degrees. Victory Archery announced this year at ATA that they will have the first production spine-aligned arrows on the market. This is a major breakthrough if you ask me, and this will really help your groups at long range.

Inserts

Inserts serve two main purposes: they provide a mounting platform for your broadheads, and they should be designed to protect the front end of your arrow shaft.

The front of the arrow takes the majority of the force when the arrow hits. For this reason, I’m usually not a fan of hidden inserts, as they can leave carbon fibers exposed.  The insert takes the blunt force of the impact, so the end of your arrow shaft should never be exposed.

The insert/outsert that Victory Archery produces for their VAP arrows are machined to very close tolerances, providing great alignment between shaft and insert. This “wrap around” design also serves as protection for the arrow shaft, and a solid mounting area for your broadheads. Another advantage of the Penetrator Adaptors from Victory archery is that the adaptor tapers from the large diameter ferrule of the broadhead, down to just over the diameter of the arrow. This produces a larger hole for the arrow to pass through, creating less friction for better penetration. There are many proprietary and aftermarket inserts available, and many provide the essentials needed. But as with any piece of equipment, you shouldn’t settle for “just good enough” here.

Fletches

A few years back I did a slow-motion test for Bohning archery and did a video that describes how an arrow corrects itself in flight and what part the fletches play. To watch this go to https://vimeo.com/53091199. Over the years I’ve tried a lot of different fletches but like most of you, I use Bohning Blazers. The basic rule of thumb when talking about stabilizing an arrow is to get it corrected and in full gyro as quickly as possible, but not so fast that you are slowing the arrow down and adding too much drag. Usually the larger the fletch, the more correction it has on it. It will be more affected by the wind but has more force carried to the animal.

When it comes to fletching jigs, you have some options. First, there is the old faithful Bitzenburger that has been used by most pro shops for years. Second, Last Chance Archery designed a new and ingenious way to fletch an arrow. It’s called The Vane Master Pro, and is an innovative tool made to give you perfection in your fletching from arrow to arrow. Using two wires to hold the vane, it gives the clamp the ability to perfectly contour around the shaft. A bit higher priced jig is the Aerovane Jig Ultimate set. This jig is built with the precision of a German Walther, and even has a meter that measures to the 1,000th of an inch, for extreme accuracy. Experiment with a few types of jigs and you will find one that best fits your budget and style.

I also love cresting arrows with unique designs and custom looks. It’s really simple and is a great way to get the kids involved. No matter if you are working on your own arrows or helping the kids with their first dozen, Bohning archery sells a little inexpensive kit with everything you’ll need. You can dip the ends of the shafts or you can just paint them with a brush. Another alternative is that you can use wraps then just fletch over them.

Nocks

The aluminum nocks being produced today are setting the standard for performance. Better arrow to string transfer due to the clean “snap” is one of the many benefits. Another is the exact alignment achieved because of machining the nock, giving exact tolerances not achievable with injection molding. But all components, regardless of material, are being built better and more exacting today than in years past. Durability, precision, and function are all to be looked at when choosing nocks and all equipment you use.

My Equipment

When it comes to picking an arrow, it’s a very individual decision. But with all the slow motion and penetration tests that I have done, I have found that small diameter arrows will out penetrate anything else. They are really expensive, but I want every arrow to count. I’m shooting the Victory Archery micro VAP, and with the spine-alignment, insert/outsert Penetrator Adaptor, and aluminum nock, I feel confident that I am shooting the best equipment available today.

Tuning arrows has become so much easier today than it was in the past, and this can enable any archer to see improved performance almost instantly. The products I shoot are a result of many years of research, lab testing, and field testing with the manufacturers and engineers. Not everyone has the privilege of doing their own extensive testing, but hopefully the results we provide can help you in finding the best equipment for your needs.

Through the years, and with over a thousand animals harvested with my bow, I’ve learned a lot about what to do and not to do. I’ve made every mistake that you could imagine, from too light a shaft, broadheads that were too heavy, too long or short, or shaped wrong. Again, my technical mind has to know and understand how and why it does or doesn’t work, which is why I do so much testing.

Before I went to Zimbabwe to hunt elephants, I spent a lot of time practicing and preparing with a heavier draw weight and arrow in order to make the shot. This involved getting the best inertia possible, and trying to achieve the highest kinetic energy possible for this task. When I was hunting elephants it was going to be the biggest hunt of my life. I mean, this is the largest animal on earth that you can pursue with a bow. The engineers at Bowtech worked to build me a bow that happened to be one of the all-time largest kinetic energy bows of all time, and had a 130 lb. draw weight. They wrapped the limbs with glue and rope to try to keep them from coming apart. This was no small task to draw this bow, and after a week of pulling the weight I felt like I was ready. I used a 1260-grain arrow with an insert that I machined to try to hold up to the impact. Even though this setup was extreme, it still required tuning of the bow and arrows for maximum performance. When you’re facing a truly “once in a lifetime” shot, you don’t want to experience failure on any level.

I’ve been lucky enough to experience many great moments in my hunting career, and I want each of those moments to end with a silent prayer and perfect arrow flight when the shot is presented. Through following these tips for equipment selection, arrow tuning and practicing your technique, you will help tilt the odds in your favor when that moment of truth arrives!