Achieving a 36-yard zero with a 25-yard sighting-in distance involves adjusting a firearm’s sights so that the point of impact matches the point of aim at 25 yards, while also ensuring the trajectory intersects the point of aim again at 36 yards. This creates a near-zero trajectory within that range, meaning the projectile will impact close to the point of aim at any distance between the two zero points. For example, a rifle zeroed this way might impact slightly high between 25 and 36 yards, but the deviation would be minimal, allowing for effective target engagement without holdover adjustments at typical self-defense distances.
This specific zeroing technique is popular for defensive firearms, particularly handguns and carbines, due to its practicality in close-quarters scenarios. By minimizing the need for holdover or hold-under adjustments at typical engagement distances, it allows for rapid and accurate target acquisition under stress. The historical context likely stems from practical experience and ballistic studies that identified the optimal balance between trajectory curvature and ease of use at common self-defense ranges. This approach minimizes sight adjustment complexity while maximizing effective projectile placement within a realistic engagement envelope.