Bow Tuning And Warm Up by Eric Vance
Okay, this is a biggie, but as promised, I’ll get into some good useful info for my fellow archers as the hunting season is at hand. Putting aside existentialist ramblings, we’ll get into the things that get the arrow to the mark. While my personal focus is traditional archery, I do own and enjoy a compound bow. I have “pretty good” familiarity with compound bow use & setup, and will try to outline the most common situations encountered by both traditional and wheel-bow shooters in their efforts toward accurate shooting. In many states, the hunting season is already under way, and I do not recommend that bowhunters make any radical changes to their equipment if they are already hitting the mark. If you do have a few issues that are noticeable and need attention, hopefully I’ll touch down on them here and help keep your shots in the “ten ring”.
First, the most important tools you’ll need for both compound & traditional bows are a bowsquare & nock pliers that have a “nock point removal” feature. I always find that string silencers are effective with “all” bows, with exception sometimes with inherently quiet selfbows. Even there, however I find the effect of silencers on any bow are useful in removing the “twang & recoil” upon release of the shot. A good tacky string wax and some nylon serving material is necessary for tying things on/into the string. For compound bows, FastFlight serving material is better for tying in peep sights where the impact & stress on the bowstring may loosen nylon material. Also for compound bows, it is good to have a “string divider” tool and, obviously, a full set of Allen wrenches for adjusting the limbs, sights, etc. In either case, a nice padded vise is a wonderful thing to free up both hands so you don’t have to call your wifey in to help you when it’s cussin’ time!
Let’s keep the horse before the cart and your bow setup – whether simply checking or adjusting – will be at its best. The sequence of checks & adjustment is important so you don’t have to do anything a couple/few times over unnecessarily. I will avoid cam & draw length adjustment because this is “advanced” setup, and will often require professional service, especially with newer bows. The ever-advancing technology with compound bows and accessories keeps a degree of challenge in staying on top of bow tuning with modern equipment.
One last thing before getting on with it. Arrow spine in relation to draw weight is perhaps the single most important thing to be sure of before you waste any time tuning. I can spend a good deal of time outlining how to figure that out, so I’m going to leave it for the moment that you “probably” have the right arrows! Contact your local shop for some input there if you need it, or feel free to email me with questions.
Here, at least, are the usual parameters in tuning for accuracy and good arrow flight. Compound bow setup:
1. Tiller adjustment.
Check this with either your bowsquare or a tape measure. Measure the distance from the END of each limb at the draw weight adjustment & attachment bolt to the string at 90 degrees. This is usually a 3/16″ Allen key screw. It is important that you measure to either the inside or outside of the string accurately, not haphazardly to one side or the other. Tighten or loosen the limb adjustment bolt to bring the string closer or farther, respectively, to the riser. The measurement to the string should be the same from the ends of both limbs. Now is the time to make any draw weight adjustments if you feel inclined to do so. Simply loosen the limb adjustment bolt to drop the draw weight or tighten to increase. Be sure that you are within the specification of allowed number of turns down from maximum draw weight or you may be at risk of damage and injury. Always check the tiller adjustment after any draw weight adjustment. Note that most manufacturers of compound bows advise that the limb bolts should never be tightened down all the way. There may be a few exceptions to that these days, but you’re always safe with the limb adjustment bolts backed off a little.
2. Arrow rest adjustment.
I’m not going to tell you how to do this in terms of “which screws to adjust” because there’s too many varieties of rests out there. You’re going to have to know what to do from experience or the text that may have come with your equipment. This can be a bit tricky and is usually done simply by eye and checked with either observing arrow flight for any side-to-side arrow flight deviance, or with “paper tuning.” If you don’t have a paper tuning setup, then just do it by eye and shoot at a background that will show the arrow in flight. A second pair of eyes is very helpful here to assist in visual tracking of “tail-left” or “tail-right” arrow flight. Adjust the rest to the right for tail-right flight and to the left for tail-left. This is easy to see when shot through paper stretched over a frame by observing the entrance point, and which way any tear in the paper may indicate. This is great for nock point tuning as well, inspecting for vertical tearing. The other adjustment to pay attention to with your rest is clearance for your fletching. Simply hold the arrow in the rest with the fletching at the rest and make sure it’s high enough – especially with “cock feather down” rests – and adjust accordingly. Other than proper clearance, it’s always good to have the rest as low as possible. Many new designs of rests dictate with their function, the correct position, but will still require left/right adjustment.
3. Nock point adjustment.
This is done with the bowsquare by determining the point of 90 degrees from the arrow rest to the string. Double-finger rests must be taken into account in so far as that the arrow is “cradled” between the fingers of the rest, sitting down in between them a bit. Check your perpendicular-to-string point with this in mind. I find that with almost all elevated rests (all compound bows and some recurve bows), that the “sweet spot” for nock point adjustment is when the underside of the arrow shaft (not the nock itself) is 1/8″ above 90 degrees to the rest. Observe arrow flight or check with paper tuning again at this point and adjust accordingly. If, when paper tuning and a tear shows above the entrance point, then raise the nock point. Conversely, lower the nock point if a tear extends below the entrance point. Minor adjustments are better than major adjustments as a rule. Once you’re happy with arrow flight, most compound shooters who use a mechanical release will install a “cushion button” below the nock when an arrow is on the string. This keeps the hard surfaces of the nock and the release jaws away from each other with the forgiveness of the rubber buffering any impact & instability in your release hand.
4. Silencer installation.
There’s a wide variety of string silencer styles out there. I’m generally a proponent of rubber whiskers. They are the lightest in physical weight and are waterproof. I don’t really care for one-piece rubber silencers. I believe them to be heavy and less effective. I’m sure there’s plenty who might argue that, but I can only speak from personal experience. Whiskers can be trimmed for best results in clearing the cables and reducing wear on them. A bow vise, or any big-jaw padded vise, is very helpful at this point (“Honey, can you drop making dinner and help me please?”). If you can clamp the bow to free your hands, do so. If not, you can rig a quick hold-down with a second chair with a padded seat and a belt. Put the belt around one leg and over one limb of the bow with the other limb on your opposite thigh. With the belt set close to the riser, brace that limb on the seat of the padded chair. Simply stretch out the leg with the belt & bow on it to pull down against your other leg and the chair. This will hold the bow well enough for you to work with your hands free. Cut the strips of rubber whisker to about 1 1/2″ and use 2 pieces for one silencer. Wax the string with good sticky string wax or beeswax to help load the two layers of rubber whisker onto the string. Wax at least two feet of serving material with the wax and cut it in two pieces. Tie the string bits onto the string with an open loop about the size of a quarter, and go twice through to start the knot, rather than the “once-through” as you might start a “square knot”. With one hand, roll the string away from you. With the other, hold the two layers of rubber against the string and roll/feed the rubber whisker material onto the string at 1/4 the distance from wheel-to-wheel. Once rolled onto the string, slip the loop over the rolled rubber to the middle and cinch it down (“Honey…….”). Tighten it firmly by pulling the string ends one way, then the other keeping tension on both ends. Now wrap the string ends around the rubber material twice each end and re-cinch & tie it off. Again, when tying off, do the “double-through” to start the knot – this will hold the tie-on without slipping while you complete the knot. Tie it like a square knot, but with an extra hitch to finish it. Burn down the cutoff string ends to seal the knot – carefully!
5. Peep installation/adjustment.
A peep sight, if used, should be installed in the string above the nock point at the distance of your “anchor point” to your eye. Use a string divider tool or a butter knife with no teeth to separate the string strands equally and insert the peep. Secure it snugly between two hitch knots with FastFlight serving material. The hitch knots should consist of at least 6 or more windings for reinforcement before tying off. If you know how to do a “slip loop” as with fly tying, that looks tidier than a surface knot. Install the rubber tubing likely supplied with it to the bow with the proper method, likely also supplied.
6. Sight adjustment.
Start with your most likely shooting distance or expected hunting shot range. This will vary from region to region and its particular terrain. Open ground will result in longer shots, and wooded cover will usually mean shots under 20 yards. I like to start with my “most likely” distance for my hunting shot, or start with 20 yards for target shooting. Simply put, if your shots hit “left of center”, move the pin to the left, and the same for hitting “right”- move the pin to the right to bring your shots to center. For high and low hits, again; if low, move the pin lower to bring the shot up. If hitting “high” raise the pin. Small adjustments now! Stay with one distance until you’re really consistent with your shots. C’mon now – we should be talking 2″ – 3″ groups at 20 yards! Any more spread than that, and you should think about hunting next year! While traditional bows and their setup are simpler overall, the setup is no less critical for best results. All we have to worry about is brace height (distance from string to throat of grip), nock point, shelf treatment, and silencers. Again, arrow spine is important, and I’d have to say more so with traditional bows than compound bows. We’re talking about “archer’s paradox” here, which simply means that the arrow must “get around” the shelf cleanly to continue on with good flight. Arrows compress on lift off, and flex away from the shelf to clear it properly. To this end, not only must the arrow be of correct spine, but also the “hard side” of the shaft should be against the bow with the cock feather on the “soft side” of the shaft. This is checked with a spine tester when the arrows are built. To that end, I will quickly say that if you have a 50# bow, we start with 50# spine as reference. Then adjust spine accordingly: