The short version of how to sight in a crossbow: start close to get on paper, shoot from a solid rest, zero the top reticle at 20 yards, then confirm 30 and 40 without touching the adjustments again.
Use the same bolts and the same nocks throughout, let the bow cool between shots, and verify broadheads separately once field points are printing where you want them.
Before the first bolt
A crossbow that is loose will not hold a zero no matter how well you shoot it. Go over the hardware before you burn a single bolt, with the bow de-cocked and the rail empty.
- Check the scope mount screws and the base screws. Snug, not gorilla tight.
- Check the limb bolts, the stock screws and the accessory rail if you have one.
- Inspect the string serving and the cables for fraying or separated strands. A worn string changes point of impact and belongs in front of a technician, not on the range.
- Sort your bolts. Same length, same weight, same nock type, same vane orientation. Set aside anything bent or cracked.
- Check every insert and point is tight. A loose point walks your groups and looks exactly like a scope problem.
De-cock or discharge into a target before any adjustment, cleaning or hardware check. Keep your thumb and fingers below the rail and out of the string path on every shot. Never dry-fire the bow, not even to release the string at the end of a session. Use a bolt into a target or your manufacturer’s de-cocking method.
Read your manual for the cocking procedure and any bolt weight minimum. Bows differ, and a bolt that is too light behaves like a dry fire.
Rest, target and distance
Shoot from a rest. A bipod, sandbags or a shooting bag all work. The goal is to take your body out of the equation so what you see on the target is the bow and the scope, not your pulse. Support the forestock, never the limbs, and never let anything touch the string path.
Use a target rated for crossbows. A bag target sized for vertical bows can be shot through, and soft foam buries bolts deep enough that you damage them pulling them out. Set it square to you, at a height that lets you shoot level from the rest.
Start at 10 to 20 yards. If you are mounting a new scope or working on a bow that has been apart, start at 10. Getting on paper close is faster and cheaper than hunting for a hole at 30. Put a large aiming point on a big backer so a wild first shot still leaves a mark you can measure from.
Let the bow cool between shots. Fast strings and rails heat up, and a string of rapid shots can shift a group in a way that has nothing to do with your zero. Two or three shots, then a pause, is the pattern.
How to sight in a crossbow at 20 yards
Twenty yards is the standard reference for the top reticle on almost every crossbow scope, because the other marks below it are calculated from that zero. Get this one right and the rest follow.
- Get on paper at 10 yards
Cock the bow, load a bolt, and take one careful shot from the rest at the center of your aiming point. You only need to know roughly where the bow is printing.
- Make a coarse correction
Adjust windage and elevation to move the reticle toward the hole. De-cock or discharge before you touch the turrets. Adjusting them always means handling the bow. Shoot one more to confirm the direction was right.
- Move to 20 yards and shoot a group
Three bolts at the same aiming point, with a cool-down between each. One shot tells you nothing. A group tells you where the bow is actually printing.
- Measure from the center of the group
Work from the middle of the three holes, not the best one. Correct windage first, then elevation, so you are only chasing one variable at a time.
- Dial the correction
Follow the click value printed on your turret cap. Many crossbow scopes are a quarter inch per click at 20 yards, but check yours rather than assuming. Count the clicks out loud so you do not lose track.
- Confirm with a fresh group
Three more bolts. If the group is centered where you want it, stop adjusting. Chasing single holes is how people spend an afternoon getting further from a zero.
Confirming 30 and 40 yards
Once 20 is set, do not touch the turrets again. Move back to 30 and shoot the second reticle. Then move to 40 and shoot the third. You are checking calibration, not re-zeroing.
If the marks are printing high or low as a set, the fix is usually the scope’s speed setting rather than the turrets. Multi-reticle crossbow scopes calculate their lower marks from an assumed arrow speed, and your actual speed depends on your bow, your bolt weight and your string condition. Adjust the speed ring per the scope manual, then re-confirm 20 before you go back out to 30 and 40.
| What you see | Likely cause | What to do |
|---|---|---|
| 20 is centered, 30 and 40 both print low | Scope speed setting is faster than the bow actually shoots | Adjust the speed ring per the manual, then recheck 20 first |
| Groups open up only at 40 | Form, wind, or bolts that are not matched | Sort bolts by weight, shoot on a calm day, check the rest |
| One bolt is always the flyer | Bent shaft, loose point or a damaged nock | Mark and retire that bolt, then reshoot the group |
| Point of impact walks as you shoot | Loose scope base, loose limb bolt or a hot rail | Stop, check every screw, let the bow cool |
| Vertical stringing shot to shot | Inconsistent cocking, so the string is not latching square | Use a crank or a rope cocker every time, never hand cock unevenly |
Scroll the table sideways to see every column.
How far you should shoot at game is a separate question from how far you can sight in. That answer depends on your bow, your practice, the animal and your state regulations. Check your regulations and your own honest group size, not a number from a video.
Multi-reticle scopes and dial-to-range scopes
Crossbow optics split into two camps, and they ask different things of you.
Multi-reticle
- Nothing to turn once it is set, so it is fast in the stand
- All the marks are visible at once
- Calibration rides on the speed setting being right
Dial to range
- One clean aiming point, which is easier to hold on small targets
- Needs a confirmed range and a dial turn before the shot
- Requires a written record of your dope for each distance
Either way, write your results down. Distance, bolt weight, point weight, temperature and where the group landed. Next season you will want that page.
Broadheads print differently, so check them
Field points and broadheads do not always land in the same place, and the gap usually grows with distance. Fixed blades catch air and steer, mechanicals are closer to a field point but not identical, and both are sensitive to how straight your bolts fly.
Verify with the exact broadheads you will hunt with, on a broadhead-rated target, starting at 20 and working out. If they land somewhere other than your field points, check bolt straightness and insert alignment first, then adjust to the broadheads, since that is what will be on the bolt when it counts.
Shoot practice heads of the same model and weight to keep your hunting broadheads sharp and true. Confirm with one or two shots from the actual heads at the end, then retire any head that has hit a target hard.
Holding your zero through the season
A zero is not permanent. Strings stretch, screws loosen and cases get dropped. Shoot a confirmation group at 20 before opening day, after any travel and after anything falls over.
Keep the bow dry and stored properly between sessions, and keep the string and rail serviced. Our crossbow maintenance post covers rail lube, string wax and off-season storage, all of which affect where your bolts land. If you are carrying the bow any distance to your spot, how you sling it matters too. Our post on choosing a sling for crossbow carry explains where webbing can and cannot route, and the crossbow sling guide goes deeper on carry positions.
For a hands-free walk in, the McLean Dynamic Retention Sling uses a patented two-point to one-point conversion, maritime grade webbing and all metal hardware. If your bow needs a second attachment point, our quick detach sling mounts cover the common conversions.
Frequently asked questions
How many bolts does it take to sight in a crossbow?
Plan on 15 to 25 if the scope is new, fewer if you are confirming an existing zero. Work in three-shot groups with cool-downs. If you are still chasing the group after 30 bolts, stop and check the hardware instead of the turrets.
Should I sight in at 20 yards or 30 yards?
Twenty, unless your scope manual says otherwise. Multi-reticle crossbow scopes build their lower marks from a 20-yard zero on the top reticle, so zeroing anywhere else throws off every mark below it.
Why do my bolts hit low at 40 yards but perfect at 20?
Most often the scope’s speed setting does not match what your bow actually shoots with your bolt weight. Adjust the speed ring per the scope manual, then re-confirm 20 yards before going back out to 40.
Can I sight in with field points and hunt with broadheads?
You can do the bulk of the work with field points, but you must verify with the broadheads you will hunt with. They can group in a different place, and the difference tends to grow with distance. Confirm on a broadhead-rated target.
Does temperature change my point of impact?
It can. Strings and limbs behave a little differently in cold, and most people also shoot differently in gloves and heavy layers. Confirm your zero in conditions close to what you will hunt in, and note the temperature with your results.
How often should I re-check my zero?
Before the season, after any travel, after the bow gets knocked over, and any time you change bolts, points, nocks or the string. A three-bolt group at 20 yards answers the question in five minutes.
