A boresighter is a very helpful, tool when sighting in a rifle to get to a “starting point”, which usually means on paper, or on the target. Once the firearm is hitting the paper, adjustments can be made to the scope to get the bullets hitting where they should be. Without the help of a boresighter, this can be a very time – and ammo – consuming task. The most common type of boresighter is a colimator, which is an optical instrument mounted to the bore of the rifle (or pistol, or shotgun for that matter) and has an internal grid to use for adjusting the scope crosshairs. Most use an arbor of the correct caliber to fit in the bore of the gun to align the colimator. The arbors are seldom real tight fits, and can fall to one side or the other at just the wrong moment. The colimator must be the same height as the scope for accurate adjustment, which is sometimes difficult since scope mounts can be of different heights and even scope diameters are not all the same.

A magnetic colimator uses a strong magnet to attach to the bore, and will not usually move during the sighting process. Proper height can be set by measuring the scope height and placing the colimator accordingly. The Bushnell Magnetic Boresighter I used to get started with my muzzle loader works very well, and is reasonably priced. Leupold also markets a magnetic version.

The Bushnell Magnetic Boresighter does a good job of getting those first shots “on paper”.

I was able to get “on paper” at 25 yards with the first shot using the Bushnell Magnetic Boresighter, which has not always been the case for me when using arbor type colimators.


About MikeH

Texas hunter and fisherman for 50 years, published outdoor writer since 1979, licensed charter boat operator from 1982 to 2013. Past Member, Board of Directors, National Association of Charterboat Operators, current member Environmental Advisory Committee to the DOE and the Strategic Petroleum Reserve. Married to Dorothy since 2000, one son, Michael who is recently married and living in Nederland, Texas. My wife and I live in Oyster Creek, Texas, near Freeport, and have a hunting property outside of Brazoria, Texas.
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