Tuning Broadheads for Accuracy

Re post from Moderator: Excalibur Marketing Dude 

 

Following a few steps when tuning your broadheads will result in increased accuracy.

ComfyBear original author:

 

In my opinion, tuning your fixed- or replaceable-blade broadheads requires a three-step process. I will list each step separately and what I do to keep my broadheads in perfect tune.

First, I attach a broadhead to one of my arrows with medium to tight pressure. Then, I spin-check it. By that I mean I rotate the arrow between my fingers on a flat surface with the tip of the broadhead acting as the apex of a spinning top. (You can also use one of the many commercial spin-checking devises on the market). If there is any noticeable "wobble" 1 to 2 inches above the insert of the arrow, the broadhead/arrow combination will not fly straight. In essence, it will "wobble" in flight.

As amazing as it sounds, some brand-new broadheads (inside the same package) will not line up with certain brand-new arrows. Generally, only one broadhead out of three will line up perfectly with a certain arrow. You have to experiment with each broadhead to find out which arrow it fits best. Perhaps this is because not all inserts are perfectly aligned -- tolerance levels fluctuate during mass production.

Second, I line up each blade of my three-blade broadheads with each (in my case) feather. In other words, when you look down the shaft from nock to tip, each feather (or vane) should line up exactly with each blade of the broadhead. If you can't line up each blade by simply twisting the broadhead tighter, you will have to heat up your inserts with a flame until you are able to freely move the broadhead. Once it's in line, allow time for the inserts to cool. On two- and four-blade models, you can either set the blades so that they ride horizontal or vertical to your sight picture. The arrows will fly straight either way.

Third, (and this is very excessive, but adds to my confidence) I place the arrow/broadhead combination on a flat surface and make sure that there are two feathers/vanes lying exactly flat and two blades lying exactly flat. If there is any slight variance, I adjust the broadhead so there is no visible difference.

Another method of tuning broadheads involves the precise calculations of a mathematician. Determining the Front of Center, or F.O.C., will reveal the aerodynamic properties of your arrows. Although there are exceptions, it is widely known and accepted that a forward balance weight of between 7 and 10 percent accompany the most aerodynamic arrows.

To determine the F.O.C. of your arrows, you must first measure the shaft from the tip of the broadhead to the end of the nock. Take this measurement and divide it by 2 to discover the arrow's center point (i.e. a 34 5/8-inch measurement -- the length of my arrows -- divided by 2 equals 17 5/16 inches). Be sure to mark this measurement with a felt tip pen.

Next, determine the balance point of the shaft, and mark its location. Divide the distance between the two marks by the overall length of the arrow and multiply by 100. (In this case the distance between the two marks of my 34 5/8-inch arrow equals 3 inches. Take 3 and divide it by 34 5/8 or 34.625 times 100, and it will equal a F.O.C. measurement of 8.66 percent). The general rule of thumb dictates that when the F.O.C. is above 10 percent, you should use a lighter broadhead; when it's below 7 percent, you should use a heavier broadhead.

In conclusion, I personally shoot a stout arrow to help alleviate problems with wind plane while shooting broadheads. I currently shoot 2317s out of my 78-pound bow. I feel that a heavier arrow will act as a better broadhead stabilizer than a lighter arrow. On the other hand, you will lose some speed shooting these types of arrows, but I feel the benefits outweigh the loss in speed. Accuracy is a lot more important to me than a faster shaft and the probability of inconsistent arrow flight.

Taking the time to determine your arrow's F.O.C. and properly aligning your broadheads can make a big difference. It could also make your setup more forgiving and produce better results. Try it for yourself. You may be surprised with the results