Product Details

Boresight Collimator Calibration


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Out of stock

SKU: SS-BC1 Category:


Boresight Collimator Calibration Service 

This service is performed in our shop. It locates the center of the the collimator grid on the axis of the bore arbor to within +/-0.5 MOA. It can be done on either new or used collimators (see below on restrictions with used collimators). Usual shipping charges apply.

Save $10 on the calibration service, when ordered with a new Bushnell Boresighter Collimator.
Go to the Bushnell Bore Sighter Collimator  page and select the HPO Calibration Service option (+$20).

Calibration of the collimator grid at the factory is generally not very good. We’ve found that new Bushnell Bore Sighter collimators are off by 2.5-4 MOA. Alignment errors as large as 12 MOA are not uncommon in used collimators, usually because previous owners tried to “calibrate” the collimator themselves.

We align the collimator grid to be parallel to the v-groove axis to which the bore arbor attaches. This process aligns the grid to within +/-0.5 MOA of the collimator arbor axis in both the horizontal and vertical directions [1]. We then place a calibration date sticker on the collimator. We also include instructions on how to use a calibrated collimator to perform common functions, such as:

  • Zeroing optical sights to the bore of the rifle
  • Diagnosing barrel-receiver alignment problems during rifle scope installation
  • Changing rifle scopes without losing zero
  • Checking a free-floated stock for barrel contact.

Procedure: New Bore Sighter. When you purchase the calibration service and a Bushnell Professional Bore Sighter (model 74-3333) together, a new Bore Sighter is pulled from our inventory and removed from its packaging. We calibrate the collimator and then place it back in the factory packaging, with all factory supplied accessories and paperwork.

Procedure: Customer’s Bore Sighter. You ship your boresight collimator to our North Carolina location. We calibrate the collimator and then place it back in your packaging, with all included accessories and paperwork. Note: you only need to send us the Bore Sighter, not the bore spuds or other packaging, instructions, etc.

Important: For us to perform this calibration service the small screw-on cap on the end of the collimator must be removable to expose the adjustment screws for the grid reticle. This service cannot be performed on BSA or Tasco boresight collimators because the screw-on cap is glued in place on these models.


  1. When the Bushnell bore arbors are maintained and used properly, reproducibility of the bore arbor alignment to the rifle bore is within +/-0.5 MOA.
  2. When used with a rifle scope that has a centered reticle, a properly calibrated collimator can be used to accurately boresight align the rings to the rifle bore. Adjusting the elevation and windage knobs to the center of their adjustment range usually locates the reticle within +/-3 MOA of the true boresight position of the riflescope tube.

Additional information

Specification Image
Specification Image
Weight .5 lbs