Arrow Ballistics Study | 2026

FoC | Practical Effects Summary

Regression results translated into practical FoC and spine changes, with 95% uncertainty ranges and the observed spread of each metric.

A note on reading this table

This table warrants a little more information on what is going on. Each row is one regression coefficient: what one model predicts about one accuracy metric (KPI) when one input changes by one unit.

  • All metrics are lower-is-better. Tighter groups, less broadhead drift. A negative coefficient means the change improves the metric.
  • Practical Effect Status. Detectable means the effect survives a strict Bonferroni correction across the 6 KPIs tested for that model term. Borderline means it is statistically significant on its own but does not survive that correction. No detectable effect means the model cannot distinguish the effect from zero.
  • Survives Bonferroni? The boolean version of the above. Survives is the strongest claim of statistical significance available in this table.
  • +5pp FoC Effect ÷ Observed Metric Spread. How big the predicted effect is compared to natural build-to-build variation. ~1.0 means the effect is as large as one standard deviation of spread across the matrix.
  • Lower / Upper 95% Bound columns are the 95% confidence range for the coefficient or the translated effect. A range that crosses zero means the effect could plausibly be in either direction, which is what typically produces a Borderline or No-detectable-effect status.

Full statistical methodology lives in the Methods page.

Ballistics Study 2026 — FoC practical effects summary.
Strict Weight-controlled ModelBroadhead Extra Drift Past Field PointMeasured FoC (%)0.006-0.4970.5090.9817330.4581.8521.0000No detectable effectNo detectable effectDoes not survive0.017-1.4921.5260.028-2.4862.5430.0150.057-4.9735.087———
Strict Weight-controlled ModelBroadhead Distance From Synthetic AimMeasured FoC (%)-0.026-0.7570.7050.9425340.4382.5291.0000No detectable effectNo detectable effectDoes not survive-0.078-2.2702.114-0.130-3.7843.524-0.051-0.260-7.5677.047———
Strict Weight-controlled ModelUntorqued Broadhead Mean RadiusMeasured FoC (%)-0.407-0.611-0.2020.0003340.3770.8870.0020DetectableImproves metricSurvives-1.221-1.834-0.607-2.034-3.057-1.011-2.293-4.068-6.114-2.023———
Strict Weight-controlled ModelTorqued Broadhead Mean RadiusMeasured FoC (%)-0.219-0.393-0.0450.0154340.6140.9010.0925BorderlineImproves metricDoes not survive-0.657-1.179-0.135-1.095-1.965-0.225-1.215-2.189-3.929-0.450———
Strict Weight-controlled ModelUntorqued Field Point Mean RadiusMeasured FoC (%)0.041-0.0150.0980.1450340.1560.2430.8701No detectable effectNo detectable effectDoes not survive0.124-0.0450.2930.207-0.0760.4890.8490.413-0.1510.977———
Strict Weight-controlled ModelTorqued Field Point Mean RadiusMeasured FoC (%)-0.051-0.1370.0360.2380330.1000.2431.0000No detectable effectNo detectable effectDoes not survive-0.153-0.4120.107-0.254-0.6860.178-1.045-0.509-1.3730.355———
No-weight / No-speed ModelBroadhead Extra Drift Past Field PointMeasured FoC (%)-0.189-0.323-0.0560.0070330.4641.8520.0421DetectableImproves metricSurvives-0.568-0.968-0.168-0.947-1.614-0.279-0.511-1.893-3.227-0.559———
No-weight / No-speed ModelBroadhead Distance From Synthetic AimMeasured FoC (%)-0.446-0.652-0.2400.0001340.4282.5290.0007DetectableImproves metricSurvives-1.339-1.957-0.721-2.231-3.261-1.201-0.882-4.462-6.523-2.402———
No-weight / No-speed ModelUntorqued Broadhead Mean RadiusMeasured FoC (%)-0.115-0.194-0.0360.0059340.1980.8870.0352DetectableImproves metricSurvives-0.344-0.581-0.107-0.574-0.969-0.179-0.647-1.148-1.938-0.357———
No-weight / No-speed ModelTorqued Broadhead Mean RadiusMeasured FoC (%)-0.159-0.203-0.1160.0000340.6200.9010.0000DetectableImproves metricSurvives-0.478-0.608-0.349-0.797-1.013-0.581-0.885-1.594-2.026-1.162———
No-weight / No-speed ModelUntorqued Field Point Mean RadiusMeasured FoC (%)0.0200.0060.0340.0077340.1660.2430.0462DetectableWorsens metricSurvives0.0590.0170.1010.0980.0280.1680.4020.1960.0560.336———
No-weight / No-speed ModelTorqued Field Point Mean RadiusMeasured FoC (%)0.008-0.0140.0310.4544330.0660.2431.0000No detectable effectNo detectable effectDoes not survive0.025-0.0420.0920.042-0.0700.1530.1710.083-0.1410.307———
No-weight / No-speed ModelBroadhead Extra Drift Past Field PointNominal Spine0.0200.0120.0280.0000330.4641.8520.0001DetectableWorsens metricSurvives——————————-1.973-1.191-2.754
No-weight / No-speed ModelBroadhead Distance From Synthetic AimNominal Spine0.006-0.0060.0180.3061340.4282.5291.0000No detectable effectNo detectable effectDoes not survive——————————-0.5970.574-1.767
No-weight / No-speed ModelUntorqued Broadhead Mean RadiusNominal Spine0.002-0.0020.0060.2607340.1980.8871.0000No detectable effectNo detectable effectDoes not survive——————————-0.2010.157-0.560
No-weight / No-speed ModelTorqued Broadhead Mean RadiusNominal Spine0.001-0.0010.0040.3614340.6200.9011.0000No detectable effectNo detectable effectDoes not survive——————————-0.1140.137-0.364
No-weight / No-speed ModelUntorqued Field Point Mean RadiusNominal Spine-0.001-0.0020.0000.1738340.1660.2431.0000No detectable effectNo detectable effectDoes not survive——————————0.0710.174-0.033
No-weight / No-speed ModelTorqued Field Point Mean RadiusNominal Spine-0.001-0.0030.0000.0533330.0660.2430.3196No detectable effectNo detectable effectDoes not survive——————————0.1460.295-0.002
Dynamic Spine ModelBroadhead Extra Drift Past Field PointMeasured Static Spine (26")17.1140.75933.4680.0409330.4511.8520.2454BorderlineWorsens metricDoes not survive——————————-1.369-0.061-2.677
Dynamic Spine ModelBroadhead Distance From Synthetic AimMeasured Static Spine (26")-6.880-30.56016.7990.5569340.4492.5291.0000No detectable effectNo detectable effectDoes not survive——————————0.5502.445-1.344
Dynamic Spine ModelUntorqued Broadhead Mean RadiusMeasured Static Spine (26")11.0074.58017.4340.0015340.4060.8870.0091DetectableWorsens metricSurvives——————————-0.881-0.366-1.395
Dynamic Spine ModelTorqued Broadhead Mean RadiusMeasured Static Spine (26")3.106-2.0118.2230.2244340.6170.9011.0000No detectable effectNo detectable effectDoes not survive——————————-0.2480.161-0.658
Dynamic Spine ModelUntorqued Field Point Mean RadiusMeasured Static Spine (26")-1.335-3.1580.4890.1451340.1510.2430.8708No detectable effectNo detectable effectDoes not survive——————————0.1070.253-0.039
Dynamic Spine ModelTorqued Field Point Mean RadiusMeasured Static Spine (26")-0.400-3.7102.9110.8064330.0810.2431.0000No detectable effectNo detectable effectDoes not survive——————————0.0320.297-0.233
Dynamic Spine ModelBroadhead Extra Drift Past Field PointTotal Insert / FACT Weight (gr)-0.012-0.0330.0090.2531330.4511.8521.0000No detectable effectNo detectable effectDoes not survive—————————————
Dynamic Spine ModelBroadhead Distance From Synthetic AimTotal Insert / FACT Weight (gr)-0.023-0.0530.0080.1414340.4492.5290.8484No detectable effectNo detectable effectDoes not survive—————————————
Dynamic Spine ModelUntorqued Broadhead Mean RadiusTotal Insert / FACT Weight (gr)0.0140.0050.0220.0021340.4060.8870.0123DetectableWorsens metricSurvives—————————————
Dynamic Spine ModelTorqued Broadhead Mean RadiusTotal Insert / FACT Weight (gr)0.003-0.0040.0100.4378340.6170.9011.0000No detectable effectNo detectable effectDoes not survive—————————————
Dynamic Spine ModelUntorqued Field Point Mean RadiusTotal Insert / FACT Weight (gr)-0.001-0.0040.0020.4654340.1510.2431.0000No detectable effectNo detectable effectDoes not survive—————————————
Dynamic Spine ModelTorqued Field Point Mean RadiusTotal Insert / FACT Weight (gr)0.002-0.0020.0060.2749330.0810.2431.0000No detectable effectNo detectable effectDoes not survive—————————————
30 entries
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