Bore sighting, a quick and often inexpensive method for initially aligning a rifle's scope, is a common practice among firearm enthusiasts. But how accurate is a bore-sighted rifle, really? The short answer is: not very accurate, at least not for precision shooting. It's a starting point, not a finishing line.
What is Bore Sighting?
Bore sighting involves aligning the scope's crosshairs with the rifle's barrel bore using a bore sighting tool. This tool, typically a rod with a sight built in, is inserted into the barrel, allowing the shooter to roughly align the scope. This process is significantly faster and easier than conducting a full zeroing procedure at the range.
Why Bore Sighting Isn't Enough for Accuracy
While bore sighting gets you close, several factors contribute to its inherent inaccuracy:
1. Inherent Limitations of the Process
Bore sighting only accounts for the alignment of the scope with the barrel's bore. It doesn't account for several crucial elements that affect bullet trajectory:
- Bullet drop: Gravity pulls the bullet downwards over distance, something bore sighting entirely ignores.
- Wind drift: Wind deflects the bullet, and its effect is not considered in bore sighting.
- Rifle twist rate: This impacts bullet stability and accuracy, a factor entirely outside bore sighting's scope.
- Sight Height: The height of the scope above the bore significantly affects bullet trajectory.
- Ammunition variations: Different types of ammunition can produce slightly different results, impacting accuracy.
2. Tool Imperfections & User Error
The accuracy of bore sighting is heavily reliant on the tool itself and the user's skill. Even minor imperfections in the bore sighting tool or errors in its placement can significantly skew the initial alignment, resulting in a significant miss at longer ranges.
3. Recoil & Scope Mounting
The force of recoil after firing can subtly shift the scope's alignment, particularly if the scope is not properly mounted. Bore sighting does nothing to address this potential shift.
Bore Sighting: A Necessary First Step
Despite its limitations, bore sighting remains a useful first step in the scope mounting process. It brings the scope's point of impact relatively close to the point of aim, reducing the time and ammunition needed for subsequent zeroing at the range. Think of it as a rough alignment to start the process.
Achieving True Accuracy: Zeroing at the Range
True accuracy comes only through zeroing at the range. This involves firing multiple shots at various distances and making scope adjustments based on the bullet's impact points. This process takes time, patience, and ammunition but is absolutely essential for consistent and accurate shooting.
Conclusion
Bore sighting offers a convenient initial alignment for a rifle scope, but it should not be mistaken for a final calibration. For accurate shooting, range zeroing is absolutely necessary. It's an essential step towards becoming a more precise and effective marksman. Consider bore sighting as a helpful starting point to save time at the range, but dedicate the necessary time for proper zeroing to ensure the accuracy you expect from your firearm.
