This sighting-in technique involves adjusting a firearm’s sights so the projectile’s trajectory intersects the point of aim at both a close range (typically 25 yards) and a further distance (50 yards). This results in the bullet’s path crossing the line of sight at these two points, creating a slight arc. For example, a rifle zeroed this way will impact slightly low at very close ranges, be on target at 25 yards, rise slightly above the line of sight at intermediate distances, and then drop back down to the point of aim at 50 yards.
This method provides a practical compromise for accuracy at varying distances, particularly with common hunting or target shooting calibers. It allows for accurate shots at both closer and mid-range targets without requiring significant holdover or hold-under adjustments. Historically, this approach has been popular due to its simplicity and effectiveness in field conditions where rapid target engagement is often necessary. It reduces the complexity of range estimation and hold adjustments for shots within the effective range of the firearm and chosen cartridge.