Nova Archery Field Guide · Arrow Selection
The correct compound bow arrow spine is the shaft stiffness recommended for your measured peak draw weight, finished arrow length, point-and-insert weight, and bow speed category. Start with the chart for the exact arrow model you intend to buy—never choose a shaft from draw weight alone.
This guide explains what the numbers mean, which measurements to collect, how common setup changes affect dynamic spine, and when to ask a qualified archery technician to confirm the selection.
What does arrow spine mean?
Arrow spine describes how much a shaft bends under load. Manufacturers commonly mark carbon shafts with numbers such as 300, 340, 400, 500, or 600. In this system, a lower number usually identifies a stiffer shaft: a 300-spine arrow is normally stiffer than a 500-spine arrow within a comparable product family.
There are two related ideas. Static spine is a standardized stiffness measurement taken with the shaft supported and loaded. Dynamic spine is how that finished arrow reacts when your bow transfers energy into it. Easton explains both concepts in its official Arrow Size Selector. Static spine gives the shaft its label; dynamic spine is the behavior you are trying to match to the complete setup.
Some flex at the shot is normal. The goal is not to find an arrow that never bends. The goal is a shaft that reacts within the intended range, clears the bow correctly, tunes predictably, and remains appropriate for its intended target or hunting use.
Collect these four measurements before using a chart
1. Measured peak draw weight
Use the bow's actual peak weight, not the number printed on the limb and not the weight you hope to shoot later. A bow scale at a competent pro shop provides the most reliable value. If you recently changed the weight, select arrows for the current setting and recheck the chart before making another major change.
If you are still deciding on a comfortable setting, start with our guide to choosing compound bow draw weight without overbowing.
2. Finished arrow length
Arrow length and draw length are related, but they are not interchangeable. A chart normally specifies exactly where to measure—often from the throat of the nock to the end of the shaft or insert. Follow the definition printed with that manufacturer's chart.
Do not cut arrows based only on a wingspan calculation. The arrow must remain safely supported by the rest at full draw, with suitable clearance for the point or broadhead. A qualified technician should confirm the finished length before cutting. Once material is removed, it cannot be put back.
3. Total point-and-insert weight
The front of the arrow may include the point or broadhead, insert, outsert, collar, and added weights. The chart may ask for the combined total. A heavier front assembly generally makes the arrow behave dynamically weaker, which can move the recommendation toward a stiffer shaft.
4. Bow or cam speed category
Some manufacturers ask for the bow's advertised speed range or apply an adjustment for aggressive cams. Use the specification for the exact bow and follow the chart's instructions. Do not substitute a chronograph result unless the chart specifically requests it.
How to choose compound bow arrow spine step by step
- Choose an arrow family first. Spine numbers are useful, but the chart for the exact manufacturer and model is the authority for that shaft.
- Measure the bow. Record actual peak draw weight and confirm the draw-length setting.
- Plan the finished arrow. Confirm safe arrow length and total front-component weight before ordering cut shafts.
- Use the manufacturer's current chart. Enter or locate the exact values, including any speed or point-weight adjustment.
- Resolve boundary cases conservatively. If the setup falls directly between groups, use the chart's own guidance or contact the manufacturer rather than guessing.
- Build one consistent set. Keep the shaft model, spine, length, components, fletching, and nocks matched across the group.
- Inspect and tune. Confirm safe clearance and use an appropriate tuning process only after shooting form is repeatable.
As a practical illustration, Archery 360's arrow-spine explanation shows how one manufacturer's recommendation changes when arrow length, draw weight, or point weight changes. Treat examples like these as demonstrations, not universal charts. Your selected shaft may use different groupings or assumptions.
How setup changes affect dynamic spine
| Setup change | Typical effect | Required action |
|---|---|---|
| Higher peak draw weight | Demands a stiffer dynamic reaction | Recheck the current shaft chart |
| Longer finished arrow | Generally behaves weaker | Recheck length and spine group |
| Heavier point or insert system | Generally behaves weaker | Use total front weight in the chart |
| Shorter finished arrow | Generally behaves stiffer | Do not cut solely to correct tune |
| Faster or more aggressive bow category | Can require a stiffer recommendation | Apply the manufacturer's speed adjustment |
These are directional effects, not instructions to modify an arrow on your own. Shortening a carbon shaft, changing components, and installing inserts require the correct tools, adhesives, tolerances, and safety procedures. Use a pro shop when you are not trained for the work.
Spine is not the same as arrow weight
Spine describes stiffness. Arrow weight describes mass, normally measured in grains. The shaft's grains-per-inch value contributes to finished weight, but so do the nock, vanes, wrap, insert, collar, point, and any added weight.
Choosing an inappropriate spine just to make the arrow lighter or heavier is the wrong order of operations. First select a safe, suitable spine. Then build the desired finished weight using compatible components while confirming that the component change has not moved the dynamic-spine requirement.
Signs your arrow setup needs professional review
- The shaft model or spine is not listed for your measured setup.
- You changed draw weight, arrow length, point weight, or front components after the arrows were selected.
- Broadheads and field points separate consistently even after form and basic bow tune are checked.
- Arrow flight is visibly erratic or groups change unpredictably.
- Components do not fit correctly, nocks vary in fit, or fletching contacts the rest or cables.
- An arrow hit a hard object or shows a crack, splinter, bend, or unusual sound during inspection.
Flight problems do not prove that spine is wrong. Grip torque, rest position, cam timing, vane clearance, nock fit, damaged arrows, and inconsistent form can produce similar symptoms. Change one variable at a time and work with a qualified technician when diagnosis requires a bow press or specialized tools.
Build the arrow around the complete bow setup
Arrow selection works best after the bow fits the shooter. Confirm draw length, establish a controllable draw weight, fit the D-loop and peep, and decide whether the arrow is for target practice, 3D archery, or hunting. Our compound bow beginner guide explains the larger setup sequence, while the parts of a compound bow provides a useful equipment reference.
If you are building a new setup, review the NOVA ORIGIN compound bow and have a pro shop confirm the bow's measured weight, your finished arrow length, and the current manufacturer chart before ordering a full matched set.
Frequently asked questions
Is a 300-spine arrow stiffer than a 400?
In the common carbon-arrow numbering system, yes: the lower number normally indicates less measured deflection and therefore a stiffer shaft. Always confirm the specification for the exact manufacturer and model.
Can I choose arrow spine from draw weight alone?
No. Draw weight is only one input. Finished arrow length, point-and-insert weight, bow speed category, release method, and manufacturer-specific rules can change the recommendation.
Does a heavier broadhead require a stiffer arrow?
Adding front weight generally makes the arrow behave dynamically weaker and may move the chart recommendation toward a stiffer shaft. Enter the total front-component weight into the current chart rather than changing only the broadhead and assuming the original selection still applies.
Does cutting an arrow make it stiffer?
All else equal, a shorter shaft generally behaves stiffer. However, arrows should be cut to a safe, correctly measured length—not shortened casually to chase a tuning result.
Should every arrow in my quiver have the same spine?
For a consistent shooting set, use the same shaft model, spine, finished length, and component build. Mixing arrows with different stiffness, weight, or components changes impact and makes tuning less meaningful.
Bottom line: Measure the bow, define the finished arrow, and use the current chart for the exact shaft. Arrow spine is a system decision—not a single number selected from draw weight—and a qualified technician is the right final check before shafts are cut or used.
Arrow selection illustrations
Continue Your Setup
Recommended Next Steps
After spine selection: Confirm the finished arrow through paper tuning, then use the field-point and broadhead group comparison before hunting.
0 comments