Accuracy and precision are frequently used as though they have the same meaning. In rifle shooting, however, they describe two separate characteristics of performance.

Understanding the difference allows a shooter to interpret a group correctly, diagnose likely problems, and determine whether the rifle requires a zero correction or whether the size of the group must first be improved.

Accuracy

Accuracy describes how closely the result corresponds with the intended point of impact.

When evaluating a group, accuracy is determined by comparing its mean point of impact with the desired point of impact. The mean point of impact is the calculated centre of the complete shot group — not necessarily the location of any single bullet hole.

If the centre of the group corresponds with the desired point of impact, the group is considered accurate overall. The individual shots may still be widely dispersed, meaning the result is accurate but not precise. This distinction is important — a widely dispersed group centred on the target may appear satisfactory, but it provides a poor probability of hitting smaller targets because individual impacts remain unpredictable.

Precision

Precision describes the degree to which repeated shots land close to one another. In practical terms, it is represented by the size and consistency of the group.

A rifle and ammunition combination that repeatedly produces a tight group demonstrates good precision, regardless of where that group appears on the target.

A tight group positioned away from the desired point of impact is precise but not accurate. The system is producing consistent results, but the zero does not correctly position those results on the target.

Precision cannot be judged reliably from a single shot. It must be assessed using a group containing enough shots to reveal the rifle system's normal dispersion. Very small groups containing only a few rounds may be useful, but they can give an overly optimistic impression of the rifle's true capability.

It is also important to recognise that a group represents the combined precision of the rifle, ammunition, optic, shooter, and prevailing conditions. Mechanical precision can only be assessed properly when as many external variables as possible are controlled.

Accuracy, Precision & Zero

One of the most important principles to understand is that adjusting the zero changes the location of a group; it does not reduce its size.

If a group is tight but positioned away from the desired point of impact, the sights or optic can normally be adjusted to move its mean point of impact into the correct position.

If the group is excessively large or inconsistent, changing the zero will simply move that large group to a different location. The cause of the poor precision must first be identified. Potential causes may include:

Practical Rifle Performance

The ideal rifle system must be both accurate and precise. It must produce a sufficiently small group and position that group over the intended point of impact.

The level of precision required depends on the size of the target and the distance involved. A rifle intended for large targets at short range does not require the same degree of mechanical precision as a rifle intended for small targets at extended distance.

As range increases, angular dispersion covers a larger physical area on the target. A rifle that appears precise at 100 metres may therefore reveal important limitations when tested farther away. This is why rifle capability should be confirmed at realistic distances rather than assumed from a single close-range group.

Ultimately, accuracy and precision should be evaluated as part of the complete rifle system. The rifle, ammunition, optic, shooter, and environment all contribute to the final point of impact.

Key Principle