Zeroing a thermal scope is slightly different from zeroing a traditional daytime optic. Since thermal scopes detect heat rather than light, your target setup and zeroing process need some adjustment. This guide walks you through the complete process.
What You'll Need
Your rifle with the thermal scope mounted
A stable shooting rest or bipod
A thermal-compatible zeroing target (hand warmers, hot water bottles, or purpose-built thermal targets)
Ammunition (10-15 rounds minimum)
A torque wrench for mount screws
Step 1: Prepare Your Target
Standard paper targets are nearly invisible through thermal optics because paper and cardboard are the same temperature as the surrounding environment. Instead, use one of these methods:
Hand warmers: Stick adhesive hand warmers to a cardboard backer in a cross or diamond pattern. These glow brightly in thermal.
Aluminum foil target: Crumple foil loosely and tape it to a backer. Foil reflects thermal differently than paper, creating a visible contrast.
Hot water target: Fill a ziplock bag with hot water and tape it to your target frame. Works great but cools down over time.
Commercial thermal targets: Purpose-built targets with reflective or heated elements. The most consistent option.
Step 2: Boresight First
Before firing a single round, get on paper with a boresight:
Remove the bolt and look through the barrel at your target from 25 yards.
Without moving the rifle, adjust the thermal scope's reticle to the same point the barrel is aimed at.
This gets you close enough that your first shots should be on target.
Many thermal scopes also offer a digital one-shot zero feature that simplifies this process significantly.
Step 3: Fire Your First Group
Set up at 50 yards for the initial zero (not 100, get on paper first).
Fire a 3-round group from a stable rest, aiming at the center of your thermal target.
Note where the group lands relative to your aiming point.
Step 4: Adjust the Reticle
Using the scope's adjustment turrets or digital zero interface:
Calculate the offset between your aiming point and the center of your group.
Adjust windage (left/right) and elevation (up/down) accordingly.
Most thermal scopes use MOA or MIL adjustments, check your manual for click values.
Fire another 3-round group to confirm.
Step 5: Move to Final Zero Distance
Once confirmed at 50 yards, move to your preferred zero distance (typically 100 yards for most hunting applications):
Set up a fresh thermal target at 100 yards.
Fire a 3-round group.
Make final adjustments.
Confirm with a final 3-round group.
Using One-Shot Zero (Digital Zero)
Many modern thermal scopes feature a one-shot zero function that makes the process much faster:
Fire one round at the target from your desired zero distance.
Activate the one-shot zero mode in the scope's menu.
Without moving the rifle, use the digital controls to move the reticle to where the bullet actually hit.
Confirm and save. The scope stores this zero digitally.
Fire a confirmation group to verify.
Tips for Maintaining Zero
Check mount torque: Verify your scope mount screws are properly torqued before every session. Loose mounts are the number one cause of zero shift.
Store carefully: Thermal scopes contain sensitive electronics. Avoid impacts and extreme temperature swings during storage.
Re-zero after travel: Always confirm zero after transporting your rifle, especially on rough roads or in checked luggage.
Record your zero settings: Most thermal scopes let you save multiple zero profiles. Use this feature for different ammunition or distances.
Browse our thermal scopes. Many feature one-shot digital zero for the fastest, easiest zeroing experience.