Broadhead Tuning
Easton Tuning Guide
2006 Shaft Selection Software Download
It is imperative that the draw length is correct for you.  90% of all bowhunters have a draw length of 29 inches or shorter!
I always tune my bows while wearing a cotton jersey glove on my bow hand. I always hunt with a glove on my bow hand so that’s the way I tune my bow. The cotton glove is a fantastic method to eliminate excessive hand torque and makes it much easier for you to repeat the same hand placement on the bow.
The first thing to do is to make sure:

        1. If you have a 2 cam bow the timing should be as close to perfect as possible.
        2. all arrows are straight (within .001) With the new generation of carbon arrows that most bowhunters now use there is no way to   straighten the shaft. Some arrows are advertised with a straightness of .006!!!! Personally, I wouldn’t touch these with a 10ft pole. If you are going to scrimp monetarily on any item of equipment it MUST NOT be your arrows!!!!! Buy a cheaper bow and spend the extra cash on the best arrows available. I think that the Easton ACC is a great shaft.
      3. all nocks are on exactly the same rotation and perfectly straight
      4. that your field point arrows are leaving the bow without deflecting off of the rest

If your fletching or the back end of the shaft is touching the rest as it leaves, you have to fix this problem
first. You are wasting time doing anything else.
Coat the fletch, nock, and the last 12 inches of the arrow with spray foot powder. This will leave a fine white coat of powder on the surfaces. Shoot an arrow into a bale (not thru paper). Carefully remove the arrow so not to touch any of the area that is coated with the powder. Inspect for any areas that has the powder removed. This will tell you if there is any rest and/or cable/riser contact. You must fix this before going any further!!

I prefer as much helical as possible and at least a 3 inch fletch to provide maximum spin to the arrow for ultimate accuracy. However, this increases the chance for fletch/shaft interference with the arrow rest.
Next make sure the broadhead is on absolutely straight with the shaft. Do the spin test on the palm of your hand.
If the arrow appears to wobble where the shaft and BH meet, the BH is not straight. Heat the insert and re-align. Unfortunately, most carbon shafts are assembled using an epoxy/super glue type adhesive and heating the point to a temperature that would allow realignment will damage the carbon shaft.
An alternative is to buy some small ‘wavy” washers and install them between the BH and the insert. This helps sometimes but not always. I can guarantee that if the BH “wobbles during the spin test, it will not shoot with acceptable accuracy
Here is a crude drawing of a 'spin tester" made with a 2X4 and 4 nails.
Rest Position:
The arrow rest should be aligned vertically so that the arrow is in the center of the rest attachment (plunger) hole.
Horizontal placement has a lot of debate. My opinion is that very few, if any, compound bows have the string in the physical center of the bow. Most are offset to the left of center for right hand shooters. Whatever distance this happens to be is the distance that the rest should be offset to the left. Matthews and PSE have this dimension marked on the grip or riser on some models of bows. Why all manufacturers don’t do this is beyond understanding.
One reason to move the rest from the proper/perfect position is in the case of excessive hand torque. Torque is usually caused by gripping (“strangling”) the riser, grabbing the bow at the moment of the shot or having the bow hand too deep. (outside the “lifeline” in the hand).
FOC = Front of Center
This is a highly overrated area of concern for most
bowhunting shots (10-25yds). IMO
You can find many “expert” websites that give the
formula for finding out your particular FOC value.
Most have erroneous info. The length of the point
does NOT figure into the FOC. The Easton Tuning
Guide on p32 specifically emphasizes this.
Easton does suggest that a 10-15% FOC is best
for broadhead tipped arrows. Even more for arrows
shorter than 26-27 inches.
Fletch, Broadhead Alignment
In my book it doesn’t make any difference. However, if you believe that it does then by all means do what you need to do!!
OK, we are ready to start shooting.
I am a proponent of paper tuning. Start at 10ft. Always correct the up/down tear first. If the nock is high move the nocking point down. If this does not correct the problem try reducing the tension on the support arm(s).
Usually, right hand shooters have broadheads that impact low, right of their field points.
Next, correct the left/right problem. Ideally this should be done by adjusting the draw weight and/or the point weight and or the length of the arrow. A nock left tear (right hander) indicates a weak shaft. Try lowering the draw weight or reducing the tip weight. I suggest making BIG changes. Lower/raise the draw weight by 6#’s or change the tip weight by at least 25grains. Shorten the arrow by 1 inch. Make the changes one at a time.
Somewhere along the line, you should be getting a decent tear/hole in the paper. The BIGGEST detriment to having a well tuned bow is PUNCHING the release. It is very difficult to tune the equipment if the shooter is HAMMERING the trigger.
Let’s shoot a broadhead!!!
Start at 15 yards for safety reasons. First shoot a broadhead. Then shoot a field point. Hopefully they will hit in the same spot.???
If the BH impacts lower than the field point we need to move the nocking point down (small increments). Or we can weaken the support arm tension more. Remember to fix the up/down problem first.
Shoot both again and make corrections. A left and right problem is fixed the same way that we paper tuned.
If the BH hits right of the FP reduce the bow weight, reduce the tip weight or possibly cut the arrow shorter.
If you cannot get the BH & FP to hit together you may want to try a different shaft size. If the BH continually impacts to the right of the FP you will need a stiffer spined arrow.
After your BH/FP hit the exact same space at 15yds, mover to a longer distance and continue to fine tune.
Make sure that the broadhead equipped shaft/s used for testing remain straight and that he BH’s are perfectly straight for the entire tuning process.
I do not use a bow quiver. I feel that their use makes it more difficult to tune my bow. If you choose to use one, test the BH/FP impact difference with the quiver on and off. I have seen as much as a 12” difference at 20 yards. It’s worth checking out!!

You may want to surf creep tuning and walkback tuning pages.

Good Luck and Great Hunting
Terry W.
A special thanks to Easton for use of their graphics
Untitled Page