Why Boresighting Isn't Perfectly Accurate: Understanding the Limitations
Boresighting, the process of aligning a weapon's sights with its barrel, is a crucial step in ensuring accuracy. However, it's important to understand that boresighting alone doesn't guarantee perfect accuracy. Several factors contribute to the inherent limitations of this method. This article delves into these limitations, helping you understand why boresighting is a starting point, not a final solution, for achieving pinpoint accuracy.
Inherent Mechanical Variations
-
Manufacturing Tolerances: Even with precision manufacturing, minute variations exist in the barrel's bore, the receiver, and the sight mounting points. These tiny discrepancies, often measured in thousandths of an inch, accumulate and can lead to slight misalignments, impacting accuracy. The manufacturing process, no matter how precise, will always introduce some level of variability.
-
Wear and Tear: Over time, the weapon system experiences wear and tear. This includes barrel wear from firing, movement of the sights due to recoil or impact, and even slight shifts in the receiver's alignment. This cumulative effect gradually reduces the accuracy of the initial boresighting.
-
Thermal Effects: Temperature changes can affect the weapon's metal components, causing expansion or contraction. This can subtly alter the alignment between the barrel and the sights, especially during prolonged use in varying temperature conditions.
Environmental Factors and External Influences
-
Ammunition Variations: Different types of ammunition, even within the same caliber, can have slight variations in bullet weight, powder charge, and overall ballistic performance. These variations can affect point of impact, regardless of how precise the boresighting is.
-
Wind and Other Conditions: External factors like wind speed and direction, humidity, and even atmospheric pressure can influence the trajectory of the projectile, introducing deviations beyond what boresighting can account for.
-
Shooter Variables: The shooter's stance, grip, breathing, and trigger control all play a significant role in accuracy. Even with a perfectly boresighted weapon, poor shooting technique will drastically impact accuracy.
Limitations of the Boresighting Process Itself
-
Indirect Measurement: Boresighting relies on an indirect measurement of the barrel's alignment. It involves sighting through the barrel's bore (often using a boresighting tool) and aligning the sights accordingly. This method introduces a degree of uncertainty and potential for error.
-
Sight Adjustment Limitations: Even after boresighting, fine adjustments may be needed to achieve optimal accuracy. The mechanical adjustments available on the sights often have a limited range, which might not always be enough to correct for all the discrepancies mentioned above.
Conclusion: Boresighting as a Foundation
Boresighting is a valuable initial step in the process of weapon zeroing, providing a reasonable starting point for achieving accuracy. However, it is not a substitute for proper zeroing at the range. Zeroing involves firing the weapon at different distances to fine-tune the sights, compensating for all the factors that influence accuracy, ensuring optimal performance in real-world conditions. Think of boresighting as establishing a baseline—a crucial first step but not the end goal in achieving pinpoint accuracy. Always follow up boresighting with thorough zeroing at the range for optimal results.
