Broadhead Tuning - August 2009
October 28, 2010
Question: I have problems with broadheads flying 6 inches to the right. I paper tuned a perfect bullet hole with my ACC 3-49 arrows at 65 pounds. With my backup bow, the field points and broadheads shoot the same. Is it a difference between two-cam bows and single-cam bows? -- Robert Musick, Selman City, Texas
I seriously doubt it is a difference between two-cam and single-cam bows. It may be a difference between the draw weights and force draw curves of the two bows. Possibly, your primary bow has a slight wiggle in side-to-side forward nock travel of the string and that may be translating into the broadhead planing. Generally, you would see that in the paper tuning process, but you may be just the right distance from the paper that you are missing this bobble.
Try standing closer and farther from the paper. I generally tune with the paper about five feet in front of the bow. That produces good feedback, because typically the arrow doesn't have time to correct before it gets to the paper. Here are a few more tips for tuning your broadheads so they hit the same hole with your field points. I call it micro-tuning because it occurs in very small steps.
Even if your bow is shooting bullet holes through paper and your arrow components are perfectly aligned, your hunting arrows still may not hit the exact same place as your field points. You can either move your sight to account for the small difference, or you can fine-tune your arrow rest.
Bob Mizek, Production Manager for New Archery Products, taught me a simple technique that really works. It seems like magic, but it's not. It is simply amazing how much difference tiny changes in rest position have on broadhead group location. Basically, if your broadheads group separately from your field points, move your rest very slightly in the direction you want your hunting arrows to go.
If the broadheads are high or low, left or right of the practice arrows, move the rest very slightly downward or upward, to right or to the left, respectively. I repeat: very slightly. These tweaks are all that's required to point your broadheads along the right initial path to hit the same place as your field points. Also, expect to move your sight pins very slightly after you finish with this step. But surprisingly, when you're done your field points and broadheads will hit the same place.
I realize this is not your problem because same arrows group well from the other bow, but a lot of guys have a problem with their arrow components not being perfectly aligned. The arrows may tune fine but when they screw broadheads on, the arrows go all over the place.
For a hunting arrow to be accurate, all its components must line up perfectly.
Nocks: It goes without saying that the nock needs to be installed so it's precisely in-line with the shaft. Most modern indexing nock systems take care of this for you, but to be safe, if you use the arrows a lot during the summer, you should replace your nocks before each season.
Shaft: The arrow shaft must be straight and perfect. Keep a dozen shafts aside to use only for hunting.
Inserts: If your inserts fit loosely when installed into the shaft, they will not all be perfectly square when the adhesive sets up. Your broadheads can end up pointing in any direction when you screw them in. Even small differences here result in huge differences 20-30 yards down-range.
Whenever the broadhead is pointing in a direction other than directly in line with the shaft, it will steer the arrow. This would be like bending the nose of a paper airplane one direction and throwing it. As I'm sure you know from experience, it will turn and dive dramatically when you throw it. If your inserts aren't lined up, one arrow might hit four inches high at 20 yards and another six inches low. Such random accuracy is completely unacceptable, and for many bowhunters a major source of headaches.
I like to keep things simple and spin tune all my broadhead-equipped arrows on the palm of my hand. If they vibrate at all, I change broadheads and try again. If I can't find a head that will spin true on that shaft, I set it aside.
Hopefully, you'll find enough arrows that have inserts properly installed to meet your hunting needs. (You can use the rest for practice.)
Fletching: A knuckleball is just as unpredictable in archery as it is in baseball. Helical fletching is installed on the arrow at an angle to make it spin and is the only choice for hunting.
As you increase the angle of the helical, you increase the stability of the arrow. I like arrows with an aggressive helical angle and I use drop away rests so the fletching never hits anything as it zips forward.
You don't have to use mechanical broadheads to shoot fast and accurate in the field this season. With a little extra attention to fine-tuning, you can be just as accurate with fixed blade heads.