Boresighting

After buying that scope yesterday, I mounted it on the rifle and this morning decided that I had an hour to boresight.

I learned to boresight in the Army, working on tanks. Tank ammo is expensive and we don't want to spend a lot of ammo getting the gun to shoot accurately. Basically, you look through a device stuck in the bore of the cannon and have the gunner align the sights with where the bore is pointed. In centerfire rifles, if you can look down the bore, we accomplish the same task without using ammunition.

Some good gun shops will mount your scope and boresight it, or the home hobbyist can purchase one of these devices. They work well if you can't see down the bore, or if you don't have a convenient right angle that you can use. I prefer to use the method I was taught in the service.

They say a picture is worth a thousand words, so lets take some pictures.

This photo was taken from my garage, looking toward a communications box that is approximately 100 yards away. I've removed the bolt from the rifle and aligned my bore with the top right corner of that box. When we look down the bore, we see the top corner of that communications box in the bore of the rifle.

Then, we simply adjust the scope so that the corner of the box is aligned with the cross hairs of the scope.

Voila! I'm boresighted. Is my rifle perfectly sighted with the ammo I'm going to use? No, of course not, and it won't be sighted-in even if I had used a high-dollar optical instrument. Boresighting is simply to align the sights with the bore. I still have to do the range work, but I'm confident that I can put the first bullet on paper, if not at 100 yards, then certainly at 50 yards, and that's where I'll start.