You released without an arrow. The bow made a sound it has never made before. Everything is fine — or nothing is fine — and you're not going to know which until you check.
This is that check.
What just happened
A dry fire is what happens when a compound bow is released with no arrow on the string. On a normal shot, the bow stores roughly 100 ft-lb of energy in the limbs at full draw. About 82 of those go out with the arrow. The arrow is doing a job: absorbing that energy, carrying it downrange, converting it to kinetic energy and flight. The bow deals with the remaining 18 ft-lb of residual — a number it's designed to handle thousands of times.
When there's no arrow, there's nothing to carry the energy away. All 100 ft-lb stays in the bow.
The tow rope
Think about towing a tuber behind a boat. You throttle up, the rope is loose, and the tuber just sits there — nothing is happening yet. Then the slack runs out. The rope goes from completely limp to completely taut in an instant, and all the boat's energy that had been building hits the tuber at once. Very funny until an arm goes flying into the water.
A dry fire is the same event. Without an arrow resisting the string, the cams and limbs accelerate almost freely from full draw back toward brace. Nearly unresisted. The system builds speed. Then the main string catches at brace. The cams hit their stop. One hundred foot-pounds of kinetic energy in the cam and limb assembly has to go somewhere, and it goes there in roughly 5 milliseconds.
That impulse — 100 ft-lb in 5ms — delivers a peak load of over 600 lb to the string, cams, and limbs simultaneously. Not over the power stroke. Not spread across inches of travel. All at once, when the system stops dead.
Why the cables survive
The control cables are almost never the failure point in a dry fire, and the reason is which side of the cam they're on.
At full draw, the cables are carrying about 209 lb each. They're the loaded side. When the dry fire snap happens, the cams rotate back toward brace and the cables unwind. They go from 209 lb of tension down to rest. They're releasing load, not receiving it.
The main string is on the other side. It's what catches the cam at brace — the tow rope going suddenly taut. It goes from nearly zero tension at full draw to taking the full impulse spike. That's why the string is the first thing to inspect, and the cables are usually fine.
What to inspect
Do not shoot the bow again until you've gone through all three of these. In order.
First — don't panic. Some manufacturers will replace cams, limbs, or other components on a first-time dry fire at no charge or reduced cost. It's worth a call to the manufacturer before you assume you're paying full retail for everything. Ask specifically about their dry fire policy.
That said, if you're past a warranty call or the damage is extensive, expect costs to climb into the hundreds quickly. Cams, limbs, and strings are not cheap, and a bow that took a serious dry fire may need several of them replaced at once.
If your bow is over 50 lb draw weight, expect to find damage. Not might find — expect. The impulse load scales with stored energy and heavier bows store more of it. A thorough inspection on a 70 lb bow that just dry fired is not a formality. It is damage assessment.
1. The string at the peep
The peep is the most likely failure point. The string body has enough safety margin to survive the impulse load — it breaks at roughly 1,680 lb, and 600 lb doesn't reach that. But the peep forces the string to open around a plastic insert at the exact moment of that load spike. That concentrates stress in a way the string wasn't designed to handle at that speed. Strand separation and cuts show up there first.
Look at the serving on both sides of the peep. You're looking for:
- Serving separation — the serving thread gapping away from the strands underneath
- Strand damage — individual strands that are cut, frayed, or kinked
- Peep displacement — the peep has moved or is no longer sitting square in the string
Any of these means a new string before you shoot again. No exceptions.
2. Cam shape
The cams take the mechanical stop of the impulse directly. Cam damage from a dry fire shows up in two ways, and you need to check for both.
Outer rim collapsed between the spokes. Think of the cam like a wheel. It has a rounded outer rim — that's where the string and cable tracks sit. It has spokes connecting the axle to that rim. The spokes are the supports. Under the impulse load of a dry fire, the outer rim is driven inward and the sections between the spokes have nothing backing them up. Those spans collapse — the rim goes flat where the spokes aren't. The cam is no longer round. Spin it slowly by hand and watch the outer profile edge-on. A smooth, consistent curve is fine. Any flat spot between two spoke junctions means the rim took the hit.
Bent over sideways. The entire cam body can tip laterally — the cam leans to one side instead of rotating true in its plane. Sight down the axle and look for the cam face running parallel to the riser. If it's angled off to one side, the cam body has bent under the impulse. This one is usually easier to see and always means a shop visit.
Also check:
- The string track for lip damage or deformation where the string seats
- Cable posts and attachment points for any visible movement or bending
- Both cams — even if only one looks wrong
A deformed cam can't be straightened back to spec. If you find one, the bow goes to a shop before it goes back in your hands at full draw.
3. Stress cracks
Limbs: Look at the limb faces and edges under good light. Stress cracks in limbs often run as hairline fractures across the limb width — not dramatic, sometimes not even obvious to the eye. Run your fingernail slowly across both faces of each limb. It'll catch a crack you can't see.
Riser: Check the limb pockets — the areas where the limb butts seat into the riser. That's where riser stress concentrates under a shock load. Also check any machined cutouts or thin sections in the riser body.
Limb bolts: Rare, but worth checking. Look for stretch marks along the bolt shank or any visible bending. A limb bolt that took the impulse load should be straight and clean. If it looks deformed, replace it before trusting the bow at full draw.
Cams: Look at the cam body itself — the spokes and the outer rim — for stress cracks. The spoke junctions are where material transitions from thick to thin, and that's where cracks initiate. Run your eye along each spoke where it meets the rim and where it meets the hub. Also check the outer rim in the sections between spokes, the same spans that can collapse flat. A crack there may run alongside a deformation or appear without it. Good light and a slow, systematic look around the full cam face. Do both cams.
If everything looks fine
A single dry fire doesn't guarantee damage. The safety margins on a properly built bow are real, and plenty of dry fires leave no trace. If nothing shows in a thorough inspection, you're probably okay.
Before you draw it again, take it to a shop and put it on a press. A press lets a tech check cam timing, cam lean, and draw stop condition without anyone standing behind a potentially compromised bow at full draw. It takes ten minutes and it costs almost nothing. Do it anyway.
If anything looks wrong at all: don't draw it. A compound bow at full draw is a compressed energy system. You have already seen what it does when that energy releases uncontrolled. Don't find out what it does from 28 inches away when the failure point is pointed at your face.
And even if the inspection comes back clean — even if the string looks fine, the cams look fine, and nothing is cracked — it's very unlikely your tune survived. The timing, cam lean, and draw stop position all depend on the bow being in the same geometry it was before. A dry fire moves things. Your bow shop should be on the list regardless of what the inspection finds.
Published 2026-09-14 · Axial Bowstrings