Adjusting a riflescope reticle using milliradian (mil or mrad) units at a distance of 100 yards allows for precise aiming corrections. One milliradian subtends to one thousandth of the distance to the target. At 100 yards, one milliradian equals approximately 0.36 inches or very close to 3.6 inches for 10 milliradians (often marked as 1 mil on scope adjustments). This provides a standardized and mathematically convenient method for compensating for bullet drop and wind drift.
This precise adjustment method is crucial for long-range shooting accuracy. It provides a consistent system applicable to various calibers and distances, allowing shooters to make precise corrections based on known ballistic data. This system has its roots in artillery and military applications, where precise aiming over long distances is essential. The consistent mathematical relationship between milliradians, range, and adjustment size simplifies calculations and ensures accuracy in the field.