Boresight, two lines that never meet

[Redleg]

Tends to happen when you over complicate things.

My problem is complicated subjects, being Artillery nothing is over complicated when it can get somebody hurt. Appreciate your reply.

 

[Bear44]

Not really, but if it too complex here, you can always go to the thread on getting the most posts, that's fairly simple.

There's a difference between "too complex" and "unnecessarily complex".

I'd much rather spend my time studying exterior ballistics to understand actual bullet flight characteristics.

 

[Redleg]

There's a difference between "too complex" and "unnecessarily complex".

I'd much rather spend my time studying exterior ballistics to understand actual bullet flight characteristics.

Hey Bear44, I appreciate your response. Thanks for the input.

 

[Fatal_Bert]

Now I'm starting to wonder if it's even possible to adjust a scopes line of site to be parallel with the line of the bore. I would think that would be beyond the maximum adjustment of the scope from the factory seeing as it would be an impossible zero.

 

[Redleg]

Now I'm starting to wonder if it's even possible to adjust a scopes line of site to be parallel with the line of the bore. I would think that would be beyond the maximum adjustment of the scope from the factory seeing as it would be an impossible zero.

Now that is some heavy thinking. Dang!!!

 

[BigMike]

You look through the bore and it is centered on a target at 25 yards then you adjust the crosshairs of the scope to the target to boresight the scope. Do the lines intersect?
http://www.ktgunsmith.com/boresight.htm

Yes, you made them intersect by adjusting the crosshairs of the scope. If you are looking for an explanation on the article and diagrams; its all calculated using physics and trig. I can try to help you understand the theory of it if you like, which is what the article is trying to explain as well. The article states, start by setting the crosshairs 2 inches above the laser bore sight dot at 25 feet. The two inches comes from an guesstimate of the height of the center of the scope above the center of the bore.

As shooters, we only care about the line of the scope as it relates to the line of flight of the bullet. Its much easier to get close a 100 yard zero with a bore sight if you have a 100 yard range and a ruler. Do a little math and see how far the bullet drops in 100 yards and adjust the cross hairs accordingly ( physics, but simple math physics). For example, if the bullet drops 5 inches in 100 yards, take the ruler to your 100 yard range and make two marks 5 inches apart, one on top of the other. Put the laser bore sight dot on the top mark, your cross hairs on the bottom mark, and all else being equal, you have a 100 yard zero. The bullet drops 5 inches from the line of the bore, hitting the point designated by the cross hairs of the scope.

I hope this answered your question; I got lost in the other replies.

 

[Redleg]

Yes, you made them intersect by adjusting the crosshairs of the scope. If you are looking for an explanation on the article and diagrams; its all calculated using physics and trig. I can try to help you understand the theory of it if you like, which is what the article is trying to explain as well. The article states, start by setting the crosshairs 2 inches above the laser bore sight dot at 25 feet. The two inches comes from an guesstimate of the height of the center of the scope above the center of the bore.

As shooters, we only care about the line of the scope as it relates to the line of flight of the bullet. Its much easier to get close a 100 yard zero with a bore sight if you have a 100 yard range and a ruler. Do a little math and see how far the bullet drops in 100 yards and adjust the cross hairs accordingly ( physics, but simple math physics). For example, if the bullet drops 5 inches in 100 yards, take the ruler to your 100 yard range and make two marks 5 inches apart, one on top of the other. Put the laser bore sight dot on the top mark, your cross hairs on the bottom mark, and all else being equal, you have a 100 yard zero. The bullet drops 5 inches from the line of the bore, hitting the point designated by the cross hairs of the scope.

I hope this answered your question; I got lost in the other replies.

Hey BigMike, good data. Thanks

 

[Jambo]

The article seems like a lot of math and calculations (some of which he goes about the hard way) to get you to the point where the rifle is "bore sighted" well enough that you can go to the range, fire a group, and adjust your sights.

Or, you could just go to the range, fire a group, and adjust your sights. It makes no difference if you're 1/2 MOA off or 8 MOA off; if you know how far your sights or scope adjusts per click, then it's just clicks - although maybe a few more of them.

But then again, I don't own a laser bore sight tool. I've always just looked through the barrel (from the receiver end!), centered the corner of my neighbor's roof in the barrel, and adjusted the scope or sights to match fairly closely. Then I go to the range, fire a group, and adjust the sights. This method has never been more than 4 MOA or so off.

 

[gunner1982]

You guys are making the concept much more complex than it really is.

Throw a ball underhand at something you are looking directly at. The trajectory of the ball when it leaves your hand has an upward angle, will cross your line of sight and then drops back to your line of sight as it reaches the target. A bullet with a properly sighted rifle does the same thing.

Got it?

Yes
Exactly, I used the "lobbing a softball" example too.

Great minds think alike??
Haha

 

[PopPop]

For most shooters, understanding Line of sight and line of bore are all that matter, that and dismissing from your mind that a bullet can ever rise above line of bore. It does indeed begin to drop and continues to drop until gravity drives it to earth.
With a properly mounted scope, centered over the bore, line of bore and line of sight are never perfectly parallel and the bullet will cross that line of sight twice, once near the muzzle and once further down range.