If you’re setting up a new thermal rifle scope, you might be wondering about the initial alignment process. Specifically, can you bore sight a thermal rifle scope like you would with a traditional day optic? The answer is yes, but the method and purpose are a bit different. Bore sighting a thermal scope is a crucial first step to get you on paper at close range, saving you time and ammunition before you begin live-fire zeroing. This guide will walk you through the practical steps and explain why it’s a smart practice for any thermal scope user.
Can You Bore Sight A Thermal Rifle Scope
Absolutely, you can and should bore sight a thermal rifle scope. While the core concept is similar to optical bore sighting—aligning the scope’s point of aim with the rifle’s barrel—the tools and visual feedback are unique to thermal imaging. It’s not about looking through the barrel at a grid. Instead, you’re using the thermal signature of a target to create a rough alignment. This process gets your first shots hitting very close to where you want them, which is especially helpful because thermal scopes often have narrower fields of view and ammo is expensive.
Why Bore Sighting a Thermal Scope is Different
Traditional laser bore sighters emit a visible red or green laser. A thermal scope cannot see that laser light at all. It only detects heat signatures. Therefore, standard bore sighting tools are useless. You need a target that emits or reflects a heat signature that your scope can clearly pick up. This fundamental difference is key to understanding the entire process. It’s a method built for the technology.
Another point is that thermal scopes often have digital reticles and zoom functions. This means the reticle isn’t a fixed piece of glass in the same way. Bore sighting helps account for any potential offset in the digital display and ensures your mechanical zero is in the right ballpark before you fine-tune it with shots.
What You’ll Need to Get Started
Gathering the right equipment makes the process smooth. Here’s what you need:
- A securely mounted thermal rifle scope, with all screws properly torqued.
- A stable shooting rest or bipod to hold the rifle perfectly still.
- A heat source for a target. Common options include a hand warmer, a small incandescent lamp, or a purpose-made thermal bore sight target.
- A safe backstop and a known, short distance (25 yards is a common starting point).
- The adjustment caps for your scope removed (don’t lose them!).
Step-by-Step Guide to Bore Sighting Your Thermal Scope
Follow these steps carefully for the best results. Remember, safety first: always treat the firearm as if it is loaded, even during this process.
Step 1: Secure Your Rifle and Target
Place your rifle firmly in its rest, ensuring it cannot move. Set up your heat source target at a close distance, like 25 yards. The target should be in a safe direction with a proper backstop. The heat source needs to be a clear, consistent point. A hand warmer taped to a cardboard box works excellently because it provides a bright, small spot for the scope to see.
Step 2: Power On and Locate the Heat Signature
Turn on your thermal scope. Look through the scope and find the heat signature of your target. You may need to adjust the focus and the brightness/contrast settings to get a crisp image. Center the rifle as best you can on the target using the rest, before you even touch the scope’s adjustment knobs.
Step 3: Adjust the Windage and Elevation
Here’s the core of the process. While the rifle remains completely stationary, use the scope’s adjustment turrets to move the reticle directly onto the center of the heat signature. You are moving the reticle to the point of aim, not the point of aim to the reticle. This aligns the scope’s line of sight with where the barrel is currently pointed. Make small adjustments and let the image settle after each turn.
Step 4: Double-Check and Confirm
Once you think the reticle is centered, take your eye away from the scope and then look back. Ensure the rifle hasn’t shifted. Make any final tiny tweaks. At this point, your thermal scope is bore sighted. The reticle should now be very close to where your bullets will impact at that distance. This means you’re ready for live-fire zeroing without wasting shots finding the target.
Common Challenges and Practical Tips
Sometimes things don’t go perfectly. Here are some tips to help.
- No Clear Hot Spot: If your heat source is too cool or too large, it will appear as a big blob. Use a small, hot source. A cup of hot water can work in a pinch, but a hand warmer is more consistent.
- Rifle Movement: Any movement ruins the alignment. Use a solid rest and consider a vise if you have one. Even a small bump means you should start that step over.
- Digital Lag: Some scopes have a slight delay. Move adjustment knobs slowly and pause to let the display catch up.
- Distance Matters: Don’t try to bore sight at 100 yards. Start close. The goal is to get on paper, not to achieve a perfect zero. The close-range alignment will translate to a much easier process at your intended zero range.
Moving From Bore Sight to Live-Fire Zero
Bore sighting is not zeroing. It is the critical pre-step. After bore sighting, you must confirm and refine your zero with live ammunition. Here’s the simple next steps:
- Take your bore-sighted rifle to the range.
- Set up a proper thermal target (one with contrasting heat panels) at your desired zero range (e.g., 50 or 100 yards).
- Fire a small group, usually 3 shots, from a stable position.
- Observe where the group hits relative to your reticle’s aim point.
- Use your scope’s turrets to adjust the reticle to the center of the group you fired.
- Fire another group to confirm. Your thermal scope is now zeroed.
The bore sighting step makes this whole process faster, cheaper, and less frustrating, as your first group will already be on the target.
Frequently Asked Questions (FAQ)
Can I use a regular laser bore sighter for a thermal scope?
No, you cannot. Thermal imaging devices detect heat, not visible laser light. A standard laser bore sighter is invisible to a thermal scope. You need an actual heat source as your target.
What is the best distance for thermal bore sighting?
A short distance of 25 to 50 yards is ideal. It provides a large, easy-to-find thermal signature and sets a solid foundation for your final zero at a longer range. Trying to do it too far away makes the initial signature hard to distinguish.
Do I still need to shoot to zero after bore sighting?
Yes, absolutely. Bore sighting is only a rough mechanical alignment. It gets you close, but factors like ammunition type, barrel harmonics, and environmental conditions mean you must complete a live-fire zero to ensure precision accuracy. Never skip the live-fire confirmation.
Can I bore sight a thermal during the day?
You can, but it can be trickier. The sun heats up everything, creating a busy thermal background. It’s often easier at dawn, dusk, or night when your specific heat source stands out more clearly against a cooler environment. Just make sure your shooting area is safe and legal for the time of day.
Is a special target required?
Not necessarily. While you can buy targets designed for thermal zeroing, many household items work. Hand warmers, small battery-operated lamps, or even a heat pack are all effective. The key is a small, concentrated, and hot signature.
In summary, bore sighting your thermal rifle scope is a simple, effective, and highly recommended procedure. By using a heat source as your reference point, you align the digital reticle with your barrel’s orientation in just a few minutes. This foundational step saves you valuable time and resources at the range, letting you move quickly to the important task of live-fire zeroing. With your scope properly aligned from the start, you can have confidence in your setup when it counts. Always remember to follow up with live ammunition to achieve a true and reliable zero for your specific rifle and load.