Archery manufacturers make shorter, faster bows because shorter, faster bows sell. That is a business observation, not a physics one. The physics says the same thing it always has: for precision target shooting, a longer axle-to-axle bow with a taller brace height is more forgiving of execution error, produces more consistent arrow flight, and gives the archer a better feedback loop through the aiming system. The tradeoff is real — speed, weight, and bulk — but it is a deliberate one. Understanding it is how you choose the right tool instead of just buying what looks good or what your draw weight spec suggests.
Axle-to-axle length — what it actually measures
ATA is the distance between the two cam axles measured with the bow at rest — not draw length, not riser length, not the physical length of the limbs. It is the span from axle to axle across the bow in its undrawn state. A 38" ATA bow is 38 inches from the center of the top cam axle to the center of the bottom cam axle. That number is fixed by the limb pockets, the riser geometry, and the limb length. It does not change between shooters at the same draw weight.
ATA is the number that matters for geometry because it determines where the cam axles sit relative to the nock point. It does not, on its own, determine string angle. String angle at the nock is a function of ATA and cam radius together — where the string actually departs the cam is set by the cam's geometry, not the axle position. Two bows with identical ATA but meaningfully different cam profiles will produce different string angles at the nock, and therefore different lateral stiffness and different feel at full draw. ATA sets the axle spacing. Cam profile determines what the string does from there.
Why longer ATA is more forgiving — the string geometry
At full draw, the string runs from the nock point upward and outward, wrapping around each cam before attaching at the string post. The two string legs form an inverted V at the nock. The width of that V is a function of both ATA and cam radius — the axle position sets the outer limit, but the actual string departure point is on the cam's surface, which may sit significantly inward from the axle depending on the cam's size and profile.
On a short ATA bow, the cams are closer together and the V tends to be narrower. On a long ATA bow, the cams are farther apart and the V tends to be wider. But this is where most archers oversimplify the argument. A large-diameter cam on a shorter ATA bow can produce a string departure point that sits farther out laterally than a small cam on a longer bow — narrowing the real-world difference in string angle between the two. ATA is the number people shop by because it is easy to compare on a spec sheet. Cam profile is harder to evaluate but equally important to the actual geometry the archer is drawing into.
The mechanical consequence is this: a wider V is laterally stiffer than a narrow one. Think of it like a tent stake on a guy wire — if you angle the wire out farther, the same tension in the wire resists lateral movement of the stake more strongly. The nock point is the stake. The string legs are the guy wires. A longer ATA bow has string geometry that resists lateral nock deflection more strongly for the same string tension and draw weight.
When an archer introduces grip torque — a slight rotational force on the handle about the vertical axis — that torque wants to push the nock point laterally. On a short ATA bow with a narrow string V, the lateral resistance is lower and the nock deflects more per unit of torque. On a long ATA bow, the wider string geometry resists that deflection more strongly. The arrow exits with less lateral deviation for the same amount of grip error. The bow is not more forgiving because the archer makes smaller errors. It is more forgiving because the same error produces a smaller output.
Why longer ATA is more forgiving — stability and mass
A longer bow is a more physically stable aiming platform. The riser is longer, which moves mass farther from the center of gravity and increases the bow's moment of inertia about both axes. A higher moment of inertia means the same external disturbance — whether from muscle tremor, wind, or shot timing variation — produces less rotational movement at the moment of release. The arrow exits from a steadier system.
Longer risers also accommodate longer stabilizer rods at the natural forward balance point, which further increases moment of inertia without requiring excessive counterweights. Target archers exploit this directly: a 38" or 40" bow with a 30" long rod and side rods is a different stability instrument than a 30" hunting bow with a 6" stub stabilizer. The ATA makes the long rod possible at a useful mass distribution. Bolt a 30" rod onto a short bow and the balance point is so far forward that the bow becomes unwieldy at full draw.
Brace height — the power stroke and the time window
Brace height is the distance from the pivot point of the grip to the string at rest. It is not the same as the AMO draw length measurement, and it is not a measure of how "aggressive" the bow is. It is a measure of how long the arrow spends on the string during the shot.
The relationship is direct: power stroke = draw length (pivot to nock) minus brace height. A 28" draw (pivot to nock, approximately 26.25" from AMO standard) on a bow with a 7" brace height produces a power stroke of 19.25". The same draw length on a bow with a 5.5" brace height produces a power stroke of 20.75". Every inch of brace height removed adds one inch to the power stroke.
What the power stroke determines is time. Longer power stroke = more time the arrow is in contact with the string during the shot cycle = more time for any input — grip torque, bow arm movement, release inconsistency — to influence the arrow before it clears the rest and stabilizes. The arrow is at its most vulnerable to external influence during those milliseconds of string contact. Everything that happens to the bow after the trigger breaks but before the arrow clears the rest is expressed in the arrow's initial direction and nock path. A shorter power stroke reduces that window.
A taller brace height is, in this precise sense, more forgiving: the arrow exits the system before execution errors have fully expressed themselves. The error still happens. The arrow just leaves before it finishes affecting the shot.
What brace height costs — speed
Every inch of brace height removed from a bow adds roughly 10 fps to the arrow's exit velocity, all else equal. That is not a marketing claim — it follows from the physics of energy storage over the power stroke. More power stroke = more distance over which the string accelerates the arrow = more kinetic energy transferred. At a typical arrow weight of 350–400 grains on a 70-pound bow, each inch of additional power stroke delivers approximately 8–12 fps of additional arrow speed. The variation depends on the draw force curve and the cam profile, but the rough number holds across most modern compound bows.
At 280 fps versus 300 fps, the arrow carries meaningfully different kinetic energy for hunting, has a different trajectory at 40 yards, and — for hunting specifically — penetrates differently. The speed matters outside of target shooting. That is why hunting bows routinely run 5.5–6.5" brace heights and advertise IBO speeds of 330 fps or more. They are optimizing for a different problem than the target shooter is solving.
Target archers shoot at known distances, often indoors, with no trajectory compensation required beyond initial setup. Speed is irrelevant to their scoring. Forgiveness and aiming precision are the only variables that count. That makes the tradeoff easy: take the taller brace height, give up the speed, and do not look back.
What ATA costs — weight, bulk, and maneuverability
A longer bow is a heavier bow. More riser material, longer limbs, longer string, additional hardware. A 38–40" ATA target rig with stabilizers, sight, and quiver frequently weighs 8–11 pounds fully configured. A 30–33" hunting bow configured for the field runs 5–7 pounds. In a treestand, in a ground blind, or on a 3D course with 28 targets, the weight difference matters every time the bow comes to full draw.
Maneuverability is the harder constraint. A 40" bow is nearly 3.5 feet across the cams. Drawing that bow in a ground blind, pivoting for a quartering-away shot through brush, or carrying it in a bow case on a pack hunt is a meaningful physical inconvenience. The bow that shoots most accurately is not always the bow that can actually be used in the conditions the shot requires.
Transport is a subtler issue but it compounds over years. A longer bow requires a longer case, takes more room in a vehicle, and occupies more space in a hotel room or camp. None of these are dealbreakers — target archers travel with long bows all the time. But they are real costs that belong in the decision.
How big is too big?
The practical ceiling for ATA in everyday use is around 40". At that length, a bow becomes difficult to maneuver through standard interior spaces, requires an extra-long hard case, and starts to challenge shot execution in elevated positions. Very few production bows exceed 40" ATA. The elite indoor target market — where the argument for maximum length is strongest — has largely converged on 38–40" as the practical upper bound.
Above 40", the marginal accuracy gains from additional string geometry become very small, while the physical inconvenience grows linearly. You are also limited by the arrow's spine requirements — an unusually long bow changes the draw force curve in ways that complicate tuning if the bow was not designed for those proportions.
Below 28–29" ATA, the string angle at the nock becomes steep enough that the bow is measurably more difficult to tune consistently, and the string geometry is short enough that precision shooting past 30 yards becomes a real challenge. Short bows exist for good reasons — primarily hunting maneuverability — but they ask more of the archer to compensate for what the geometry cannot do.
The right number for each use case
These are not rules. They are the ranges where most serious archers have found the tradeoffs to work out favorably for each application:
Indoor target (Vegas, Lancaster, 18m) — 36–40" ATA, 7–8" brace height. Speed is irrelevant. Distance is fixed and short. Maximize forgiveness and stability. Weight is acceptable because the archer stands at a line. The upper end of this range is correct for the best shooters who have also prepared the rest of the system.
Outdoor target (50m, field archery, 3D tournament) — 33–38" ATA, 6.5–7.5" brace height. Distance varies, so trajectory matters more than at indoor. Some speed is useful. But the accuracy argument still tilts longer — outdoor target archers who step down to shorter bows for "outdoor feel" are usually giving up more than they gain.
3D roving and field unmarked — 33–36" ATA, 6–7" brace height. The archer is moving, carrying, navigating terrain. Some concession to weight and bulk is warranted. The range of shooting distances and angles is wide enough that maneuverability has practical value. This is where the tradeoff genuinely becomes competitive — a 38" bow is not objectively wrong here, but it is noticeably inconvenient over a long course.
Hunting — whitetail, tree stand, ground blind — 30–34" ATA, 5.5–7" brace height. The shot window is short, the range is moderate, the environment is constrained. Maneuverability, weight, and speed are real operational requirements. Accuracy still matters, but the shot distances and conditions rarely expose the forgiveness deficit of a shorter bow the way 20 yards at an indoor target will.
Hunting — western, backcountry, pack-in — 30–33" ATA, 5.5–7" brace height. Everything is harder and heavier in the backcountry. Pack weight, transport constraints, and shot angles in terrain that does not cooperate all push toward shorter and lighter. The tradeoff tips more toward the compact package here than almost anywhere else.
Why most bows are not as long as they could be
The majority of compound bows sold in North America are hunting bows, and the majority of hunters prioritize speed, weight, and compact size. The market follows the majority. Target-specific bows are a smaller segment. Manufacturers who build exclusively for that segment — Mathews with the Title series, Hoyt with the Concept and Alpha AX lines — produce 36–40" bows at the upper end of the range specifically because that is where the physics says the target argument is strongest.
There is also a cultural element. A 340 fps IBO number is easy to put on a box. A wider string V and a more stable hold at full draw are harder to advertise. Speed is tangible and measurable at the pro shop chronograph. Forgiveness requires an archer to actually shoot the bow across many rounds before the effect becomes visible in the score. Marketing follows what sells quickly.
None of that means shorter bows are bad choices for their intended applications. A 30" ATA hunting bow in the hands of a prepared archer at ethical hunting distances is completely adequate. But "adequate for hunting" and "optimal for precision target archery" are different standards. The archer who brings the hunting bow to indoor target and wonders why the groups are wider is comparing the wrong reference.
Connecting the two — ATA and brace height together
ATA and brace height are related but independent. A 38" ATA bow can have a 5.5" brace height or a 7.5" brace height depending on how the riser and limb pockets are designed. A 30" ATA bow can have a 7" brace height. The two numbers answer different questions: ATA governs the string geometry and lateral stiffness, brace height governs the power stroke and shot timing window. Both matter, and they need to be evaluated together.
A long ATA bow with a short brace height is a peculiar combination — it uses its geometry advantage for string stiffness, but then keeps the arrow on string long enough to expose that advantage to execution error during release. It is not common because bow designers who build for target shooting tend to optimize both simultaneously. When you see a 38–40" ATA bow spec'd with a 7"+ brace height, that is not coincidence. The designer is stacking both forgiveness mechanisms in the same direction.
Conversely, a 30" ATA bow with a 7" brace height is a reasonable middle ground for an archer who needs some concession to maneuverability but wants the brace height protection. The string geometry is not ideal for long target distances, but the short power stroke still limits shot cycle exposure. Some field and 3D archers operate in exactly this configuration intentionally.
Published 2026-08-18 · Axial Bowstrings