Basic Bow Tuning - Part 2

by Cujo Cooley
BowCountry.com Staff Writer

If you remember, last time we went over the basics of setting up a bow. Topics discussed were tools, arrow selection, rest setup, and above all else, safety. Proper safety procedures must be followed at all times when handling or shooting a bow. Also, note that when handling or shooting a bow, any number of catastrophic failures may occur that can cause serious injury to yourself or others. You are solely responsible for the safe operation and handling of your bow.

When we last parted, we had the bow ready with some basic settings and adjustments. The next step is to test fire the bow to see if our settings are correct or need fine tuning. There are many methods of shoot tuning a bow; short range group tuning, bare shaft tuning, long range group tuning, and paper tuning. What we will cover today is paper tuning. One thing I need to mention here is, paper tuning is only one of a myriad of tuning tools available to the archer. The law of a perfect tear is not absolute. Some bows perform best when a less than perfect tear is seen in the paper. The ultimate test to any tuning system is the end result. How do the arrows group? If the arrows are grouping tightly at all reasonable distances, it might be safe to say that everything is fine.

For paper tuning, we'll need to get out the paper tuner, discussed in the last segment, and set it up in front of a suitable, safe backstop. You will need about 3-5 feet behind the paper tuner, and will be shooting from roughly 10 feet in front it. Set it up so that you are shooting flat out in front of you with your bow at arm level. Stick a large sheet of newsprint or butcher’s paper taut onto the paper tuner and we are ready to begin.

Now you need to draw and fire an arrow through the paper, being sure that you have made a good, clean shot. A poor release will make a poor tear, but we’ll get to that later.

By looking at the hole just made in the paper we can tell a lot about what the bow is doing. One thing I need to point out here is, we are looking at tuning and adjusting from the standpoint of a right-handed release shooter. Left-handed shooters should note that this information will apply to them in reverse. For finger shooting, paper tuning is an accepted and useful tool, but results can be effected by poor release as well. Another useful method for finger testing is bare shaft tuning.

The goal we are after for now is commonly called a "bullet hole" or perfect tear. A perfect tear indicates clean arrow flight from the bow. You may find during group tuning, however, that a perfect hole is not what your bow likes to do best. For example, it has been my experience, that many one-cam bows group better with a slight high and left tear. More on this later.

Horizontal Tears:

These two images are (from left to right) a left tear and a right tear. Note how the point enters the paper and the shaft and fletchings follow to one side or the other. A side tear can be indicative of several things, including rest setting and arrow selection errors.

Right Tear:

Fingers:
Arrow is too stiff. Try adding point weight to make the arrow act weaker, or increasing draw weight. Also suggested is to choose an arrow of a lighter spine or to lighten the cushion plunger tension. Also, making small rest adjustments towards the bow may help.

Release:
Rest too far right. Move the rest to the left in small increments.

Left Tear:

Fingers:
Arrow is too weak. Try decreasing point weight to make the arrow act stiffer, or decreasing draw weight. Choosing a stiffer arrow, increasing plunger tension, or slight rest adjustments away from the bow may also help.

Release:
Rest is too far left. Move the rest to the right in small increments. Arrow is too stiff. Select a weaker arrow, decrease draw weight, or increase point weight.

General Notes:

A left or right tear can also indicate things common to finger and/or release shooting. Ensure that you have adequate clearance of the cables and rest. Look closely at the arrow, as it is nocked on the string, and make sure that you have clearance. If everything looks ok, and you still suspect a clearance problem, one of the best investigating methods is to use spray powder to see collisions in the flight path. Simply spray the back half of the arrow with powder and fire a shot through the bow. Any impact will be readily visible on the powder coat and residue will be left on the offending object. Poor or irregular shooting form can also be a culprit in poor paper tuning results. If you do not have a repeatable grip, consistent anchor, or if you have other form flaws, your shooting will suffer. A qualified coach or shooting professional is needed to evaluate your form and make any corrections.

Vertical Tears:

These two images are of a high and low tear. Generally, high and low tears indicate rest or nock height adjustment or clearance issues.

High Tear:

Fingers:
Nock point too high or rest interference. Make small adjustments and if you still are having poor results, perform the powder test outlined above.

Release:
Same as above, but also check launcher stiffness. The tension may be too high.

Low Tear:

Fingers:
Nock point too low. Make adjustments and re-check

Release:
Same as above or rest tension set too low.

General Notes:

As well as the nock and rest setting mentioned above, there can be issues with cam timing and tiller settings that can cause the high and low tears. Also, keep in mind that inconsistencies in shooting form, as mentioned in the left and right tear section, can contribute to high and low tears as well.

Multidirectional Tears:

The most often seen and sometimes least understood tear of all is the multidirectional tear. Generally speaking, the way to attack a multidirectional tear is to start at one side and go from there. You can fix either the left and right or the high and low first, then move on to the other. It is much easier this way as you will be able to track what changes produced what results if you are only working on one issue at a time.

Bare Shaft Tuning:

The bare shaft tuning method is very effective for finger shooters. To begin bare shaft tuning, you will need at least 3 fletched arrows and, preferably, 3 unfletched arrows, although 1 or 2 unfletched will be acceptable. You need to have a target stop that will stop the arrows without allowing them to kick. Be sure to set your target in a safe shooting area that allows you to have a minimum of 10 yards from the target.

Porpoising:

Porpoising is the up and down kick of your arrow in flight, and is usually caused by an incorrect nock point setting. It is important to get the nock height setting correct first, because some left and right issues can be nock point related.

Start by shooting your 3 fletched arrows into the target, then, aiming at the same spot as before, shoot the bare shafts.

If bare shafts hit above fletched shafts - your nocking point is to low. Make small adjustments until you have all the arrows hitting the same group.

If bare shafts hit below fletched shafts - your nocking point is too high. Make small adjustments until you have all the arrows hitting the same group.

Fishtailing:

Fishtailing is the side to side movement seen in a poorly flying arrow. It is mostly a result of arrow rest adjustment and arrow stiffness.

Start by shooting 3 fletched arrows at the same 10 or 15 yard mark as used in the porpoising test. Aiming at the same spot, shoot the bare shafts into the target. It is likely that the bare shafts will be either left or right of the fletched shafts.

If bare shafts hit right of fletched shafts - your arrow is too weak. Try a stiffer shaft, a stiffer plunger setting, a lighter point weight, or decreasing draw poundage to fix.

If bare shafts hit left of fletched shafts - your arrow is too stiff. Try a weaker shaft, weaker plunger setting, heavier point weight, or increasing draw poundage to fix.

General Notes:

It is generally accepted that when the bare shaft impacts either slightly low and left or slightly low and right, that the bow is tuned. It is possible to micro tune the bow to hit the same point as a fletched shaft. It takes a lot of time and you will be quite proud of yourself when you accomplish this goal. If you wish, you can try bare shaft tuning from longer distances, but is highly suggested that you start close and work back slowly. I have seen bare shafts take a 90° turn at about 35 or 40 yards downrange. It can be dangerous to anyone or any objects nearby.

Summary:

Now that we have spent some really intimate, quality time with our bow, and have applied all the lessons learned from the basic setup all the way through to shooting and tuning the bow, it is time now to think about tossing all this great paper tuning info out the window. As discussed in the beginning of this article, paper tuning is only one of a number of tools available to the archer. After paper tuning, I believe that group tuning is the single most common form of tuning a bow that is used today, and for good reason. The next logical step after paper tuning is to go out and shoot for groups.

Starting at 20 yards, shoot for the tightest group you can get. As you gain confidence and proficiency, work back to longer and longer distances. You will find that there are a lot of subtle changes you can make to a bow, concerning mostly nock and/or rest adjustments, that will greatly effect the grouping of the bow. You will also find that sometimes you will try an adjustment that just can’t be beat at 20 yards, but at 50 yards, isn't worth two cents. The sweet spot in your setup that offers the most forgiveness and the tightest groups is what you want. You’ll have to work at it but you can find it.

One method I use to really test the tune of a bow is to use a shooting machine. The shooting machine is the easiest way to eliminate human error from any bow and to also have verifiable test results. For those individuals and Pro Shops truly serious about getting maximum performance, having a shooting machine on hand is one easily identifiable mark.

Remember to write everything down, including adjustments and results. You will find that sometime down the road this information will be invaluable as a setup or tuning tool. Perhaps even the most valuable tuning tool in your archery tackle box.

Aaron "Cujo" Cooley is a successful archer, bow hunter, and co-owner of Baxter's Specialized Archery, located in Covington, Ga. As well as catering to the bow hunter and target shooter for their equipment needs, Baxter's specializes in custom set up and tuning of target and hunting bows for discriminating archers. If you would like to contact Cujo or Baxter's Specialized Archery, you can call toll free in the U.S. 1-800-BAX-3345 or look them up on the world wide web at http://www.baxtersarchery.com.