Boresighting a rifle scope is done to assure that the cross hairs are aligned with where the center line of the bore is pointing. Learn about laser bore sighting devices with advice from a gun store owner in this free video on cleaning guns.
O.k., we're going to talk a little bit about boresighting a rifle scope on a rifle. And what you're actually doing is assuring yourself that the cross hares on that scope are aligned with where the center line of the bore is pointing. There's several different ways to do that. Back in the old days you used to be able to put the gun in some type of a rest, a very solid device, remove the bolt from the firearm and take a good look down the bore at something some distance away. Once you have that rifle locked in to place and aimed directly through the center line of the bore at something, you look through the scope and adjusted the scope to where the cross hares were on the same place. Then you shot it in after the end. We've come a bit since then. So now we have a couple different types of devices called a bore scope. This is a optical device that has a grid in it right direct in the dead center and on it is attached what they call a spud, different sizes for different calibers. That spud fits nice and snuggly right down the bore. Again, you lock in this device so it's good and stable in the gun. As you look through the scope where the cross hares are, you set this up so this grid is perfectly level with the cross hares. You've leveled the scope to the gun. Now you're going to have this level. Once you've done that you'll sight down the scope at the cross hares and what you're doing is adjusting the cross hares on that scope to the center line of the grid. What the grid has is x crosses like this, one center line. The center of that is the center of the bore, move directly upward so it's in line with the scope. Once you've lined the cross hares on the scope with the center cross hares on this, you should be real close to dead center. Then you may want to adjust it up a little bit if you're going to be sighting it in for distance. That's the easiest way. Another thing they've come out with which I won't show you but I'll talk about is a laser bore sighting device. You usually need twenty five feet. The laser again, fits in the bore very snuggly and tightly so it's in a direct line with the bore. You put the gun in device, shine that laser dot twenty five feet away on a grid on the wall. Again, a one inch cross hare grid, then you'll adjust the cross hares on the scope to where they hit dead center on that laser dot. There's a couple different kinds. Some of them are lasers that fit in to the bore. They also make specific calibers that fit right in the breech of the gun just like a cartridge. Fit right in to that breech, they're dead center on the bore, they shine that little laser dot out on the wall, and you adjust those scope cross hares right to the center of that dot.