Boresight, two lines that never meet

[Redleg]

What if it's perpendicular?

7pt62THOR, perpendicular in reference to???? Use this picture to point it out. Thanks

 

[7pt62THOR]

7pt62THOR, perpendicular in reference to???? Use this picture to point it out. Thanks[/QUOT

The shooting bench at the range? I was just goofin' brother!

 

[Bear44]

That is my point, we talk about different procedures and mish mash an answer. Boresight is an alignment of two instruments while zero is the elimination of the all the effects on a bullet's trajectory to the best of one's ability.

This is exactly why bore-sighting a rifle is simply the first step in actually zeroing the rifle. All it is meant to do is get you on paper at a reasonably close range so you can then actually zero the rifle by adjusting actual POI.

I've read through your other threads about this, too and think you expect much more precision from bore-sighting than it is possible to get. I would not take a shot on a big game animal beyond 25 yards with a rifle that had only been bore-sighted and even within 25 yards I would feel uncomfortable about it.

 

[Bear44]

20 moa alters the angle on the line of displacement not the line of sight. The line of sight is the line that runs through the center of the scope to infinity and the line of bore is the line that runs through the bore to infinity. The difference between them is the height of the center of the scope above the center of the bore. In boresighting, this is the short leg (triangle) the long leg is the line of the bore with a target at 25 yards. They create a 90-degree angle. The line of sight will not move otherwise the scope height would have to be different every time you adjust the scope. From the line of sight, there is a line of displacement that offsets by the movement of the sight setting to get the crosshairs on the target at the end of the line of bore. The hypotenuse is the line of displacement that slopes downward to meet the line of bore. The line of sight and the line of bore run parallel and never meet. This is boresighting, not zero, no ballistics.

No, bore-sighting is meant to get the line of sight and the line of bore to intersect at close range. It is not a 90% angle and the two lines do not run parallel.

 

[MilSpec308]

You’ll never be able to get the two lines to do any more then run parallel. The moment you change the angle of either line, they’re destined to intersect at some point. The only way to get them to run parallel, is to have a view of reference within the barrel(Bore) itself. To sight in a rifle, at some point, the lines have to intersect

 

[Redleg]

This is exactly why bore-sighting a rifle is simply the first step in actually zeroing the rifle. All it is meant to do is get you on paper at a reasonably close range so you can then actually zero the rifle by adjusting actual POI.

I've read through your other threads about this, too and think you expect much more precision from bore-sighting than it is possible to get. I would not take a shot on a big game animal beyond 25 yards with a rifle that had only been bore-sighted and even within 25 yards I would feel uncomfortable about it.

Hey Bear44, I do not disagree with what you just wrote, I too think that boresight is the 1st step. You have to zero. It is a two step process.

 

[Porter Rockwell]

Good info here.

 

[Redleg]

You’ll never be able to get the two lines to do any more then run parallel. The moment you change the angle of either line, they’re destined to intersect at some point. The only way to get them to run parallel, is to have a view of reference within the barrel(Bore) itself. To sight in a rifle, at some point, the lines have to intersect

Hey MilSpec308, I agree you have to reference from within the barrel itself, and the red line in the picture below shows a line running through the center of the scope. From the scope there is a line that slopes downward, that is the adjustment of the crosshairs to the target that is seen on the line of bore. this is a boresight an alignment of scope to the bore and the next step is to zero.

 

[ReservoirDawg10]

I haven't read through the whole thread yet, but the amount of false information being spewn is pretty impressive.

 

[Redleg]

I haven't read through the whole thread yet, but the amount of false information being spewn is pretty impressive.

I would not say false information, more like unproven data that needs to be worked by more than the person that puts the post up.