What is Bore Sighting?
Introduction
Imagine this: you’ve just mounted a brand-new scope on your favorite rifle. You’re itching to hit the range, eager to test its performance. But before you can start stacking shots, you know there’s a crucial first step – getting your scope aligned with the barrel. You reach for a bore sighter, a tool promising to speed up the process. But a nagging question arises: *How accurate is a bore sighted rifle* going to be? Will your shots be close enough to paper, or are you in for a day of frustration and wasted ammunition?
Bore sighting, a simple yet effective technique, aims to get your rifle’s scope roughly aligned with the barrel’s bore. It’s a starting point, a preliminary adjustment that can save you time, money, and a whole lot of headaches. But what level of precision can you really expect? Let’s dive into the world of bore sighting, exploring its mechanics, accuracy, and limitations, to give you a comprehensive understanding of this essential gun maintenance practice.
Definition
At its core, bore sighting is a process of visually aligning your rifle’s sights (be it a scope or iron sights) with the barrel’s bore. The barrel, after all, is the pathway your bullet takes, and your sights must correspond with that trajectory. The ultimate goal isn’t pin-point accuracy right off the bat, but rather a significant starting point to help get your shots on target.
The principle behind bore sighting is straightforward. You’re looking down the barrel and aligning your sight with the point you perceive the bullet to be traveling from that barrel. This is achieved without firing any rounds, making it an efficient first step when setting up a new optic or re-installing an existing one.
Equipment Needed
The beauty of bore sighting lies in its simplicity. You don’t need a fancy arsenal of tools. You’ll need a few essential items:
- A Bore Sighter (Optical or Collimator): An optical bore sighter has a reticle, like a crosshair, that aligns with the bore. Collimator bore sighters often mount in the chamber or muzzle of the rifle.
- A Stable Rest: A solid rest, like a bench or a rifle vise, is vital to keep your rifle stationary.
- Target: A blank target provides a visual point of reference.
- Cleaning Rod (Optional): A cleaning rod is useful for confirming the direction of the bore.
- Screwdrivers and/or Allen Wrenches: For adjusting the windage and elevation on your scope.
Process
The procedure typically involves these steps: First, you secure the rifle in your rest. Then, you use the bore sighter (often placed into the bore itself, or attached to the muzzle or chamber) to get a visual line of sight down the barrel. Next, you look through the bore sighter at a target, ensuring that the crosshairs of the bore sighter are centered on a given point. Finally, you use the scope’s adjustment knobs to center the scope’s reticle (crosshairs) on the same point on the target.
Accuracy Expectations of Bore Sighting
General Accuracy
So, just *how accurate is a bore sighted rifle*? The answer is, it can be reasonably accurate, but it’s not a substitute for live fire. You shouldn’t expect a perfectly zeroed rifle immediately after bore sighting. The real benefit of this approach is that it gets you on paper, or at least very close to it. This saves you precious time and expensive ammunition.
When you go to the range, you should expect your shots to be within a certain range of your point of aim. This distance from the point of aim can vary depending on a few factors, but a good starting point is often within a few inches at 100 yards. In other words, the center of your group should be somewhere on the paper within that general vicinity of your crosshair.
Factors Influencing Accuracy
The accuracy of the result depends on a multitude of different factors. Firstly, the quality of your bore sighter plays a significant role. Optical bore sighters, with their more intricate reticles and precise calibration, tend to offer better precision than some simpler models. Secondly, the skill and carefulness of the user are paramount. Take your time, make precise adjustments, and double-check your work. Lastly, the condition of your rifle is crucial. A worn barrel, for instance, can slightly affect the bullet’s trajectory, influencing bore sighting accuracy.
Limitations of Bore Sighting
Does not replace live fire zeroing
While bore sighting is a valuable tool, it’s important to understand its limitations. Above all else, it does not replace the need for live fire zeroing. Think of bore sighting as your first step, but the range is where the real refinement happens. It is a starting point and no more.
Potential for Inaccuracy
Several factors contribute to potential inaccuracies in bore sighting. Mechanical variations in the rifle, no matter how small, can cause slight misalignments. Issues such as imperfections in the scope rings or slight discrepancies in the receiver can add up.
Parallax, the apparent movement of the reticle relative to the target when you move your eye, is another potential issue. It’s crucial to ensure you are properly aligned behind the scope during bore sighting, as parallax can lead to inaccuracies.
Finally, the bore sighters themselves aren’t always perfectly accurate. Different brands and models will have different levels of quality. If the bore sighter isn’t perfectly aligned with the bore, the results will be off.
Bore Sighting vs. Other Sighting Methods
Comparison with live fire zeroing
Let’s consider how bore sighting compares to other methods of sighting a rifle. The most critical comparison is with live fire zeroing.
Live fire zeroing, where you actually shoot your rifle and make adjustments based on the bullet’s impact, is considered the most accurate method. It accounts for all the variables affecting your bullet’s trajectory, including your ammunition and the environmental conditions. Bore sighting prepares the way for live fire zeroing.
Live fire zeroing involves a time and ammunition trade-off. It takes more time, and it costs money. A poor start will also cost you your targets and make the live fire process longer. This is why you should always start by getting your scope or iron sights *as close as possible* to your point of aim using the technique of bore sighting.
Comparison with other methods
Bore sighting is also different from other methods. You can use laser bore sighters. These use a laser beam emitted from the bore to indicate the bullet’s likely point of impact. While laser bore sighters are convenient and easy to use, they can sometimes be less accurate than optical bore sighters, as the laser beam can be affected by minor misalignments.
Tips for Improving Bore Sighting Accuracy
Choosing the Right Equipment
Maximizing the accuracy of your bore sighting is vital for a smooth zeroing experience. Here are some helpful tips:
First, choose high-quality equipment. Invest in a reputable bore sighter, such as an optical bore sighter. Good quality tools will provide better results. Second, ensure proper alignment. Set up your rifle in a stable rest, and carefully align your bore sighter with the bore. Make sure the reticle is centered. Finally, follow best practices. Take your time, make small adjustments, and double-check your work.
When Bore Sighting is Most Useful
Bore sighting is a valuable practice in several specific scenarios. It’s particularly useful when you’re mounting a new scope, because it offers a starting point, so you won’t waste ammunition trying to get on paper. The same holds true when you remove and reinstall your scope. It can also be incredibly helpful before a live fire zeroing session, saving you time and ammo.
Conclusion
Summary
So, how accurate is a bore sighted rifle? The answer is that it’s a very useful first step, but it’s not the final answer. You can expect to get your shots on paper within a few inches at 100 yards using this technique.
Bore sighting provides a vital first step, but it’s the live fire session that ultimately determines your rifle’s true zero.
Final Thoughts
Remember to always bore sight your rifle before heading to the range. This will save you time, ammo, and a whole lot of frustration. It’s a simple practice that pays dividends in the long run, contributing to your overall shooting experience. With the right approach, you can have a highly accurate, reliable rifle.
