Using a bore sight for zeroing a rifle is an easy, inexpensive way to ensure that your weapon will hit what you aim it at. It is faster and less ammunition-expensive than trying to zero the weapon by firing three- to five-round groups. It is also a safer method for those who live in congested areas, where shooting live ammunition must be limited to their time on the range or in the hunting woods.
BSA produces a bore-sight device that is inexpensive and simple to use.
Unload and clear your weapon. Remove all ammunition from the weapon and lock the bolt or firing mechanism in the open position. Visually inspect the chamber of your weapon to ensure it is clear.
Select the appropriate "bore stud" from your BSA Boresighter kit. This is contingent on the caliber of your rifle. The bore studs are labeled according to caliber.
Attach the bore stud to the Boresighter and screw the bore stud into the Boresighter device hand tight.
Gently insert the bore stud into the muzzle end of your weapon. Be careful to not dent or scratch the edges of the bore, which could affect accuracy when firing the weapon.
Look through the scope of your rifle at the reference grid pattern inside the Boresighter. Adjust the bore stud inside the barrel if necessary to level the grid-pattern reference in accordance with the level of your scope cross-hair or reticle.
Adjust the windage and elevation knobs of your rifle scope to align the cross-hair or reticle of your scope with the reference grid pattern inside the Boresighter. Your rifle and scope combination is now bore-sighted.
Follow the manufacturer's instructions included with your rifle scope to complete the zero process at an authorized range or safe shooting location.
- Ensure that your weapon is unloaded before inserting the bore stud.
- If your bore stud does not insert easily into the muzzle, do not force it. Remove it and verify that you are using the appropriate bore stud for your caliber of rifle.
- Be certain that you have removed the bore stud at the end of the bore-sight process. Failure to do so can result in a blocked barrel, leading to catastrophic failure of the barrel. This can result in severe injury and/or death.
- Firearms can be hazardous. Please seek competent, professional instruction. Contact the NRA for help locating a local firearms safety instructor.
- Find out the "field zero" or "battlefield zero" of your cartridge/rifle combination and zero your weapon at that range. As an example, a 62-grain .223 round in a 16-20 inch barrel has a "battlefield zero" of 300 meters when zeroed at 250 meters. This means that if point of aim/point of impact intersect at 250 meters, any round you fire from 0-300 meters will be inside of a 6-inch circle around your point of aim.
- "FM 3-22.9 Rifle Marksmanship;" U.S. Army Infantry Center and School; 2003
- "MCRP 3-01A Rifle Marksmanship;" U.S.M.C. School of Infantry; 2006