Bore sighting ?

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Travis299

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I decided to bore sight check my Accura V2 50 & WIN M70 30-06. Both rifles have the scope mounted 1.5" above the bore & of course both rifles allow a clear sight down the bore. When I bore sight at a target at 55 yards both rifles seem, to me that the scope cross hairs are a couple of inches above the center of the bore AND both rifles were sighted in previously. I have double checked both rifles BUT have not been able to shoot either one and plan on doing so in the near future. My question is how could this be possible as the bullet must start to drop the instant it leaves the muzzle. Thanks for any help.
 
Moved this from Announcements.

A scope sets around 1.5" above the center of the bore. (as an example) Line of sight is not the same as bullet path obviously. The higher the scope is above the bore the more the intersection changes. Line of sight is always straight as far as this is concerned. Bullet path is always an arch. If you are sighted in at 100yards, its still climbing at 50 yards but will intersect somewhere before it reaches 50 yards also.
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Good info GM

I think I remember reading somewhere that 13yds is the ideal range to manually bore sight (looking through the bore) - that is what distance I use and it has worked well for me many times.
 
Good info GM

I think I remember reading somewhere that 13yds is the ideal range to manually bore sight (looking through the bore) - that is what distance I use and it has worked well for me many times.
I concurr I bore sight at 13 yards! Then shoot a 25 yard target. From the 25 yard target my prime goal the is to get the windage set. And will then adjust elevation and re-adjust windage as necessary at 100 yards.
 
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For my own boresighting, I have a fairly inexpensive Sightron magnetic boresighter.
It has a very strong magnet that goes on the end of barrel. Once centered, you turn on the laser, point at a target at 25 feet or so. Make your adjustments and you're good to go.
I'm usually pretty good on paper at 25 yards for my initial sight in at the range.
 
I have a question. If you've already shot and zeroed both rifles, why the need to boresight? Maybe I missed something but it seems an unnecessary step to me.
 
I have a question. If you've already shot and zeroed both rifles, why the need to boresight? Maybe I missed something but it seems an unnecessary step to me.
Hot day & nothing better to do so I decided to check the bore site of my rifles. I cannot understand how the cross hairs of the scope line up above the bore sight of the rifle. The bore of the rifle MUST indicate the absolute maximum of the elevation of the POI as the projectile starts to drop as soon as it leaves the muzzle.
 
You are absolutely correct, the bullet starts dropping the instant it leaves the barrel.

What you are looking at is an optical illusion. To shoot a gun accurately with a scope, the barrel has to be aiming slightly UP compared to the scope and the scope has to be aiming slightly Down compared to the barrel. That means those will intersect at some point. Because you are bore sighting at a close distance, they have not intersected yet. But the bullet is still “rising” because it is aimed upward slightly. If you keep moving the target back more and bore sight again, eventually the bullseye and the crosshairs will be exactly in the same spot, and from that point on, the bore sight spot will always be above the crosshairs (because the bullet is dropping)

What you describe sounds like these rifles are sighted in for longer range. In that case it takes a longer distance before the bore site line crosses the scope line
 
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Line of sight is straight
Axis of the bore is aiming UP
So you will have an arch with straight line of sight running thru the arch at 2 points.
 
You are absolutely correct, the bullet starts dropping the instant it leaves the barrel.

What you are looking at is an optical illusion. To shoot a gun accurately with a scope, the barrel has to be aiming slightly UP compared to the scope and the scope has to be aiming slightly Down compared to the barrel. That means those will intersect at some point. Because you are bore sighting at a close distance, they have not intersected yet. But the bullet is still “rising” because it is aimed upward slightly. If you keep moving the target back more and bore sight again, eventually the bullseye and the crosshairs will be exactly in the same spot, and from that point on, the bore sight spot will always be above the crosshairs (because the bullet is dropping)

What you describe sounds like these rifles are sighted in for longer range. In that case it takes a longer distance before the bore site line crosses the scope line
If sighted in correctly you should be zeroed at two points in the bullets trajectory. See GM54's earlier post #2.
 
Correct, nothing I said contradicts that. But the bore line of sight will always be above the scope line of sight once is crosses the crosshairs the first time. The bullet "rises" above the scope line of sight and then drops back to zero before falling below that line. The bore line never drops, but the bullet does.

They say a pic is worth a 1000 words, and GM54s pic shows what I said better than my words. But seems like he still didn't quite understand.
 

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