The type of nock changes the size of the group
1 study
The summary today
There is a single test, done for another purpose, and the differences it finds are large. While preparing a series of tests on shaft straightness, a research team shot straight X7 arrows fletched at 0.9 degrees, with vanes on the 2315s and feathers on the 2712s, from a compound on a machine at twenty-five metres, and saw the group change with the nock alone: on the 2315s the G nock, fitted with a second adapter, gave 44 millimetres, the 3D Super 33 and the MicroLite Super 27; on the 2712s the group went from 32 millimetres with the 3D Super to 15 with the MicroLite. The authors suggest that what matters is the length of nock between the end of the shaft and the string groove, about 3.7 millimetres for the MicroLite against 11.7 for the 3D Super. The order does not follow length alone, though: the G, at 8 millimetres, gave the worst group, and needed an extra adapter that may put the nock out of line with the shaft. It is a single test, with no statistics, and the methods give ten shots per arrow in one place and eight in another, without saying which applies to the nock tests: nock type seems to matter, and the reason is still a hypothesis.
Also phrased as: "nocks and grouping"; "microlite nock"; "pin nock"; "nock adapter"; "nock alignment"
In practice
Nocks are chosen mainly for how they hold the string, and the common view is that they matter little to the group compared with shaft and vanes.
Evidence
-
2017
For Equipment tests Published later
Hoyt Pro Comp Elite compound on a Hooter Shooter machine at 25 m, X7 arrows straight to ±0.001 inches fletched at 0.9 degrees (Diamond 235 vanes on the 2315s, feathers on the 2712s), group as the diameter of the smallest circle containing every hole. X7 2315: G nock with a second adapter 44 mm, 3D Super 33 mm, MicroLite Super 27 mm; X7 2712: 3D Super 32 mm, MicroLite Super 15 mm. Distance from shaft end to groove: MicroLite about 3.7 mm, G pin 2.5, G 8.0, 3D Super 11.7. The authors suggest that this length and the concentricity of the adapter are what count; for the number of shots the methods say ten per arrow in one place and eight in another, without tying either to the nock tests.
Effect of arrow shaft straightness on arrow grouping · James L Park, Patrick J Aitchison, Adam J Bielby, Vincent Bleakley, Trent P Carberry, Richard M Ellis, Richard D Kerner, Andrew D MacDonald, Danie Oosthuizen, Scott B Pankhurst, Konstantinos Psarakis
Status history
- 2017 Reported With X7 arrows shot from a machine at twenty-five metres, straight and fletched at 0.9 degrees, changing only the nock changes the group a great deal: on the 2315s the G with a double adapter gives 44 millimetres, the 3D Super 33 and the MicroLite Super 27; on the 2712s the 3D Super 32 and the MicroLite 15. The shorter nocks, with the groove nearer the end of the shaft, give the best groups, but the G, shorter than the 3D Super, is the worst and had an extra adapter. A single test on equipment, with no statistics: reported.
Related
Related articles
- Does better equipment put points on the scorecard? What shooting machines and archers showShooting machines, archers handed a bow that is not theirs and blind ratings: what the studies say about how much equipment counts towards your score.
- Choosing and matching competition arrowsWhich spine to choose and how alike the arrows in a dozen are: charts, weight, the stiff side of the shaft, straightness and nocks, as studies measure them.
- When to retire an arrow, and why a shaft snaps on releaseWhich knocks damage an arrow, why a shaft snaps on release, and what the tests say about straightness, wear and defective arrows.
Research lines
Cite
Campagna, M. (2026). The type of nock changes the size of the group (Version 1). In Evidence Registry. Retrieved 16 October 2026, from https://matteocampagna.com/en/registry/equipment/nock-type-group-size
@misc{campagna2026_coccalarghezzagruppo,
author = {Campagna, Matteo},
title = {The type of nock changes the size of the group},
year = {2026},
howpublished = {Evidence Registry, matteocampagna.com},
url = {https://matteocampagna.com/en/registry/equipment/nock-type-group-size},
note = {Version 1; accessed 2026-10-16}
}
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