By Russell Thornberry
Every bowhunter has had a mystery arrow that, for no apparent reason, just wouldn’t fly right. Most of us give up and set that arrow aside, which is the right thing to do with an arrow that simply won’t cooperate. But that’s setting aside time and money.
If your bow is well tuned, the problem is likely curable. Arrow tuning is a matter quite apart from bow tuning, and it is less understood by most bowhunters.
Tuning an arrow to a specific bow involves numerous considerations that are crucial to acquiring perfect arrow flight. The first is choosing the right spine or arrow stiffness for the bow. An arrow that is too stiff or too limber will be impossible to stabilize. But if an improper arrow spine is at fault, all such arrows will be impossible to stabilize. Here, I am specifically addressing that one arrow in the bunch that is a flier.
The other crucial factors, assuming your arrow is properly spined for the bow from which it will be shot, fall into one of several categories: shaft cutting, nock alignment, insert alignment, vane clearance and broadhead alignment.
Let’s examine the process of preparing an arrow from a bare shaft to the finished product.
If you have seen an arrow shaft cutter in use, you know that the shaft is being cut as the tip end of the arrow shaft is pushed into the cutting blade from one side. Many archers roll the shaft into the cutting blade in an attempt to get a more even cut, but this process is still very imprecise. If the entire shaft was being pushed into the cutting blade at a perfect 90 degrees, the cut would be better, but that’s not how shaft cutters work. In fact, one of the least known culprits in bad arrow performance results from this side-swing shaft cutting process. If the tip of the shaft is not cut at a perfect 90-degree angle to the centerline of the shaft, then it is guaranteed that the threaded insert cannot be glued in at proper alignment with the shaft.
Thanks to the ingenious folks at G5 Outdoors LLC, there is now a perfect solution for truing up the tips of the shafts before installing the threaded insert. The tool is called the Arrow Squaring Device (ASD), and it allows you to grind the tips of your aluminum or carbon shafts perfectly square. With this done, you’re ready to glue in your threaded aluminum or carbon insert. G5 makes ASDs for both.
Most archers would never suspect that the forward face of the threaded insert can vary in thickness from one side to the other, causing the broadhead to be misaligned with the shaft. But this is a very common problem.
I was recently building a dozen arrows for an upcoming hunting trip, using the ASD to square the cuts on the shafts before installing the inserts. When I was sure all my shaft cuts were completely square, I glued in my first insert and screwed in a broadhead for a spin test. To my horror, the broadhead wobbled fiercely. I twisted the insert in the shaft several times, but the broadhead would still not spin true. So, I covered the face of the insert with a black magic marker and then used the aluminum ASD to grind down the face of the aluminum insert. I was amazed to find that the thickness of the insert face varied dramatically from one side to the other. When the black ink was honed from the entire face of the insert, I reinstalled the same broadhead and, to my amazement, it spun like a top! I shudder to think how many times I’ve thrown uncooperative arrows away, thinking they were hopeless fliers.
That doesn’t have to happen anymore!
Installing the nock to perfect concentricity with the shaft is a must or the arrow will not fly true. An arrow spinner is also a must to find out if your nock is properly aligned. The glue-on plastic nock should initially be twisted onto the conical butt of the arrow shaft without glue.
Twist it on until it stays on the shaft and spins true on the arrow spinner. Then glue on vanes or fletchings. After the vanes or fletchings are secured to the shaft, pull the nock off the shaft and glue it in place with Fletch Tite, making sure the nock is properly aligned with the fletching to ensure proper clearance with the arrow rest.
Put the shafts in an arrow spinner and check the nock again before the glue dries, in case it wobbles. If it wobbles, twist it and recheck it until it spins true.
The more modern uni-nock system is very handy because the nock is pressure-fit into a precision pre-installed bushing in the arrow butt, ensuring alignment and the ability to twist the nock for vane alignment. Since no glue is used, the nock remains tunable within the shaft. It is important to note, however, that the face of the aluminum bushing, where it makes contact with the shoulder of the nock, might not always be perfectly square. In such a case, a bad nock alignment is possible. But now, thanks to the Arrow Squaring Device, the face of the bushing can also be honed to a perfect fit.
Once your complete arrow is assembled and nocks, inserts and broadheads spin perfectly, the last measure is to be sure your vanes clear your arrow rest. Feather fletchings are certainly more forgiving in this regard, but they lack the durability of plastic vanes.
The slightest contact between a vane/fletching and the arrow rest can throw your arrow out of perfect concentric flight. One way to determine such contact is to rub lipstick on the vanes and then take a shot. The contact point is wherever the lipstick appears on the arrow rest. That’s why dropaway rests have become popular in recent years. A properly functioning dropaway rest eliminates fletching contact, but don’t be fooled into thinking you don’t have to tune your bow. A dropaway rest must be tuned for good arrow flight just like any other rest.
If you use a two-prong rests, a vane with a helical twist might be impossible to use without making unwanted contact. The narrower the gap between the prongs, the straighter the vane will have to be. An exception to the vane contact problem is the Whisker Biscuit arrow rest. All the vanes or fletching make contact with the inner bristles of the rest, but since the contact pressure is equal on all the vanes, it does not cause the arrow to fishtail or porpoise. Conversely, one vane banging against an arrow rest can cause an arrow to wobble in flight.
Paper tuning is the ultimate test to check for concentric arrow flight. Once your arrow, with a target point, passes through paper at 8 feet, there are no secrets. Unless your arrow cuts a perfect hole without tearing up, down right or left, or a combination thereof, you can be sure something is out of whack and that your arrow tipped with a broadhead is not going to fly.
Many bowhunters don’t understand the ramifications of a broadhead-tipped arrow that porpoises or fishtails in flight. Since the arrow is not flying concentrically, when it hits its target, instead of having all its energy driving ahead in a straight line behind the broadhead, a lateral or vertical tail-slapping occurs, which stops penetration in its tracks.
Even the most powerful bows won’t penetrate if there is radical non-concentric arrow flight. For whitetails, one doesn’t need such a heavy bow as long as the arrow flight is concentric. This is why some light bows seem to get better penetration, even with the same broadhead, than more powerful bows. More power cannot cure poor arrow flight.
Archers have never had it so good. All the tools needed for perfect arrow flight are at our disposal. We owe it to the sport of bowhunting and the game we hunt to take advantage of them.