The short version of how to sight in a compound bow: confirm the peep is aligned and the sight is levelled, set your top pin at 20 yards until three arrows land centered, then leave it alone and set each remaining pin at its own distance by moving only that pin. Windage is set once on the top pin and inherited by the rest.
If a lower pin will not line up with the ones above it, the answer is almost never more elevation. It is peep rotation, a sight that is not level, or arrows that are no longer what the sight was set for. If you are still building a repeatable anchor, start with the fundamentals of sighting in a bow and arrow.
Confirm these before you touch a pin
Most time wasted on a compound sight goes on adjusting pins to compensate for something that was not a pin. Run this list first.
- Sight hardware. Dovetail bar, bracket, housing, every screw.
- Rest and launcher arm. If the rest moved, your tune moved and your settings went with it.
- Arrows. Same spine, length, point weight, nocks and fletching. Spin test each and set aside any wobble.
- String, cables and D-loop. A string that has crept changes where arrows land long before it fails, and a stretched loop moves your nock height.
- Draw length and weight. If either changed since the sight was set, expect to start over.
Never dry fire a compound. All that stored energy in the limbs and cams has nothing to go into, and a dry fire can destroy the bow and injure you. Do not draw with no arrow nocked, even to check a peep, unless you are certain you can let it down under control. Inspect strings, cables and servings for fraying or separated strands before every session, and take anything questionable to a pro shop with a press. Shoot into a target rated for your bow, and know what is behind and beyond it.
Peep alignment and peep rotation
The peep is a rear sight, and the reference that makes every pin repeatable. Two things have to be right.
Height
At full draw, with your eyes closed, settle into your anchor and then open them. The peep should sit in front of your eye with the housing centered in it. If you have to lift or drop your head to find it, the peep is in the wrong place, and every shot worked around it teaches a bad anchor the sight will faithfully record.
Rotation
It also has to come around square at full draw so you look through the hole rather than the edge of it. A peep that arrives cocked usually means a string needing twists added or removed, which is a press job. Sort it first: a peep that rotates differently in hot and cold weather gives you a bow that appears to lose zero for no reason.
Draw and anchor ten times with your eyes closed, opening them only once settled. If the peep arrives in the same place all ten times, it is set. If it wanders, fix that before spending an arrow on pins.
Second axis, third axis and angled shots
A bubble level can lie to you in two separate ways.
Second axis is whether the bubble reads level when the bow is vertical. Set it with the bow held upright against a plumb line, then adjust the sight until the bubble agrees. Get it wrong and you cant the bow on every shot, which pushes impact sideways and worsens with distance.
Third axis is whether the bubble still reads level when you tilt the bow up or down. It only shows up on angled shots, which is why it bites treestand and mountain hunters. With it off, you hold a level bubble on a steep downhill shot while the bow is actually canted, and the arrow goes wide.
To check it, hang a plumb line, aim at it on the flat with the bubble level, then aim at the same line steeply up and steeply down. The housing should stay aligned and the bubble should still read level. If not, adjust third axis per your sight’s manual, usually a screw that pivots the housing toward or away from you.
Setting the top pin at 20 yards
Twenty yards is the anchor distance for the whole stack. It sets windage for every pin, so if it is off, every pin below is off the same way.
- Get on target at 10 yards first
One or two arrows with a new sight, so your first group at 20 lands on the target face.
- Move the whole housing, not just the pin
Make coarse corrections by sliding the entire bar, saving pin adjustment for fine work.
- Shoot three arrows at 20
Same aiming point, same anchor, same grip. Watch the bubble every shot, because a canted bow here bakes an error into the whole stack.
- Set windage from the center of the group
Follow the arrow: move the sight the direction the group landed. This is a whole-sight adjustment, not a per-pin one.
- Set elevation on the top pin only
Move it up or down to follow the group. Small steps, three arrows after each, and stop the moment it is centered.
- Lock it down and write it down
Tighten the set screw and note the bar position. Every pin below references this one.
Pin by pin: 30, 40 and 50
From here it repeats with one strict rule: only the pin you are working on gets adjusted. Step back to 30, aim with the second pin, shoot three arrows and move that pin to follow the group. Then 40 with the third, 50 with the fourth.
Verify the top pin afterwards, because it is easy to nudge one while tightening its neighbour. If a pin will not come into line, read the table.
| What you see | Likely cause | What to do |
|---|---|---|
| Every pin off the same way horizontally | Windage was never right, or the bow is canted | Re-set windage on the top pin at 20, watch the bubble |
| Windage drifts on the longer pins | Bow cant, or second axis not set | Check the level against a plumb line first |
| Groups only open up at the longest pin | Arrow flight, mismatched arrows or fatigue | Tune, sort arrows by weight, shorten the session |
| Fine on the flat, off to one side uphill or downhill | Third axis | Set it against a plumb line at steep angles, re-confirm 20 |
| Zero shifts between sessions with nothing changed | Peep rotation, loose hardware or a creeping string | Check hardware and peep arrival, inspect the string |
Scroll the table sideways to see every column.
Your longest pin should be a distance you can honestly hold a group at, not the furthest the sight will go. What you can shoot at a target and what you should shoot at an animal are different numbers, set by your worst group and your state regulations.
Single pin sliders and the tape
A slider replaces the stack with one pin on a moving housing and a marked tape. The trade is knowing the range and dialling before the shot.
Multi-pin stack
- Nothing to adjust once set, so it is fast when a shot appears
- Every distance visible at once, and you can hold between pins
- Busier picture, and pins cover more of the target further out
Single pin slider
- One clean aiming point at every distance
- Needs a confirmed range and a dial before the shot
- Depends entirely on the tape being right for your setup
Sight the pin in at 20 yards as you would a top pin and mark that position on the bar. Move to a longer known distance, dial until the pin is dead on, and mark that too. Those two marks define the spacing your bow needs, so either pick the printed tape whose marks line up with both, or fit a blank tape and write your own as you confirm each distance. Then check one distance between your marks and one beyond, because a tape that matches at two points can drift at a third.
Arrow speed and pin gaps
The distance between your pins is a function of how fast the arrow leaves the bow and how much it slows on the way. Faster setups produce pins that sit closer together. Anything that changes speed changes those gaps: draw weight, draw length, arrow weight, point weight, string accessories and cam timing. This is why copying someone else’s pin spacing from a forum post does not work.
To predict your gaps rather than discover them one arrow at a time, measure your arrow speed on a chronograph with the arrows and points you will shoot, then put that number, your arrow weight and your peep to sight distance into an archery ballistics calculator. Treat the output as a hypothesis and the target as the referee. Crossbow scopes work the same way, a speed setting driving the lower reticles: see how to use a crossbow scope and how to sight in a crossbow.
What to re-check after any change
A compound sight is only valid for the setup it was set with. When any of these change, confirm 20 yards first.
- New arrows or point weight. Spine, length and shaft weight all move impact, and the effect grows with distance. Broadheads need confirming on a broadhead-rated target, starting at your closest pin.
- Draw weight adjusted. Backing the limb bolts out changes speed, so the longer pins move most.
- New or twisted string and cables. Peep rotation and nock height both move. Assume you are starting over.
- Rest moved, or the bow was in a press. Re-tune, then re-sight.
- The bow was dropped. Check hardware first, then shoot a confirmation group.
Keep notes: bar position, tape number, arrow spine and length, point weight, draw weight and the date. Next season that page is the difference between a five minute confirmation and a lost afternoon.
The last variable is transport. A bow swinging off one shoulder gets knocked into trees and truck frames, and knocked hardware moves. Carrying it hands free keeps the bow controlled and your hands free for a climb. Our tree stand carry post covers hauling a bow up and down, and choosing a sling for crossbow carry covers where webbing routes without fouling the shot. The McLean Dynamic Retention Sling is a patented two point to one point conversion in maritime grade webbing with all metal hardware.
Frequently asked questions
Do I adjust windage on every pin or just the top one?
Just the top one. Windage is a property of the whole sight, so set it at 20 and inherit it down the stack. If lower pins seem to need their own, you are almost certainly canting the bow or your second axis is not set.
Why do my arrows hit left on downhill shots but not on the flat?
The classic third axis symptom. The bubble reads level while the bow is canted, because the housing is not square to the string when the bow is tilted. Set third axis against a plumb line at steep angles, then confirm 20 yards on the flat.
How far apart should my pins be?
However far apart your bow puts them. Gaps depend on arrow speed, arrow weight and peep to sight distance, so there is no number to copy. Measure your speed on a chronograph, run it through an archery calculator, then confirm on the target.
