Help Mounting and Bore Sighting Scope

[Argon Glen]

Years ago I bought a rifle and had an unused scope mounted on it. I never used it until recently when I took a long range shooting class. It was then that I found I could not dial past 400 yards (turret ran out). Ideally the scope was not what I wanted anyway so rather than try to resolve the issue I bought a new one.

I removed the old scope and rings, attached the new rings to the existing 2-piece Picatinny rail, and wasn't able to bore sight the new scope. I found that even with elevation turned all with way down the cross hairs were still about 18 mils high (at 32 yards). That's 62 MoA. Given two scopes, with only the rail in common, have an elevation problem I started measuring the two pieces of Picatinny. They seem to be the same, neither seems to have any angle to it. Regardless, I started swapping their positions and rotating them in hopes that some different orientation would fix the problem. No luck.

What am I missing? How do I go about fixing this? Are there 70(+) MoA rails?!

* Sako A7 300 Win Mag
* Previous scope - Zeiss Conquest 6.5-20x50 (MoA-MoA, gunsmith that mounted the scope provided 2-piece Pic rail and rings)
* New scope - Nightforce NX8 4-32x50 F1 (Mil-Mil, new Nightforce rings)

Thank you.

 

[nt7332]

What is the model of the gun?

 

[Argon Glen]

Updated original post.

 

[Argon Glen]

Shims seem to be less than ideal (stress on the scope tube) and aren't up to the task of making such a huge correction.

 

[ShtrRdy]

Iys possible your new scope has a zero stop and the zero stop is preventing you from dialing down further. Follow the directions for the zero stop and adjust it so that it's 'out of the way'.

 

[243winxb]

Nighrforce should have instructions on how to mount a scope. Or Youtube. Google it.
Bushnells chart. The scope adjustments should be centered first, then shim. If windage is off a lot, buy a mount with windage adjustment.

Something like this? Talley Long Action Sako A7 20 MOA Picatinny Base,

 

[243winxb]

Found this- When shooting at extreme ranges, many shooters find their riflescope lacks the necessary elevation travel. The Nightforce Wedge Prism is offered in 2 variants, 50 MOA or 100 MOA, that install forward of the riflescope to increase the effective elevation travel. The Wedge Prism optically shifts the incoming image to the riflescope by a precise elevation value, which directly adds to the available elevation travel within the riflescope.

 

[Argon Glen]

Iys possible your new scope has a zero stop and the zero stop is preventing you from dialing down further. Follow the directions for the zero stop and adjust it so that it's 'out of the way'.

The scope does have a zero stop, but I don't think that's the issue. The specs for the scope indicate 26 mils of elevation and I can dial 28.

Good thinking though.

 

[Argon Glen]

Found this- When shooting at extreme ranges, many shooters find their riflescope lacks the necessary elevation travel. The Nightforce Wedge Prism is offered in 2 variants, 50 MOA or 100 MOA, that install forward of the riflescope to increase the effective elevation travel. The Wedge Prism optically shifts the incoming image to the riflescope by a precise elevation value, which directly adds to the available elevation travel within the riflescope.

I am familiar with the product, however I don't believe it's the right way to address the issue.

Thanks for the suggestion though.

 

[misterc01]

Iys possible your new scope has a zero stop and the zero stop is preventing you from dialing down further. Follow the directions for the zero stop and adjust it so that it's 'out of the way'.

Second that - had the same issue. I returned a scope as defective for the same issue. I did not realize untiI I got a call that when they checked out the scoep - it was the zero stop setting and not a bad scope.

 

[Glenn Montague]

Iys possible your new scope has a zero stop and the zero stop is preventing you from dialing down further. Follow the directions for the zero stop and adjust it so that it's 'out of the way'.

This would be my first guess too. Ran into this situation myself a couple of days ago when I took a new scope to the range for a quick zero. You would think manufacturers would put the zero stop at the bottom of the range of adjustment before they ship their scopes to avoid this situation.

 

[DMP25-06]

[QUOTE="Argon Glen, post: 197 I found that even with elevation turned all with way down the cross hairs were still about 18 mils high (at 32 yards). That's 62 MoA.

Did you fire shots at 32 yards , and the bullets punched holes approximately 20" above your point of aim ?

Or , if only optically bore sighting , no shots fired , and your crosshairs are above the center of the target , turn the elevation turret UP , which will move the crosshairs downward toward the center of the target .

I would remove the 2 piece bases and replace them with a quality 1-piece 20 MOA picatinny rail , then re-mount the scope and check again .

 

[Paper boy]

Years ago I bought a rifle and had an unused scope mounted on it. I never used it until recently when I took a long range shooting class. It was then that I found I could not dial past 400 yards (turret ran out). Ideally the scope was not what I wanted anyway so rather than try to resolve the issue I bought a new one.

I removed the old scope and rings, attached the new rings to the existing 2-piece Picatinny rail, and wasn't able to bore sight the new scope. I found that even with elevation turned all with way down the cross hairs were still about 18 mils high (at 32 yards). That's 62 MoA. Given two scopes, with only the rail in common, have an elevation problem I started measuring the two pieces of Picatinny. They seem to be the same, neither seems to have any angle to it. Regardless, I started swapping their positions and rotating them in hopes that some different orientation would fix the problem. No luck.

What am I missing? How do I go about fixing this? Are there 70(+) MoA rails?!

* Sako A7 300 Win Mag
* Previous scope - Zeiss Conquest 6.5-20x50 (MoA-MoA, gunsmith that mounted the scope provided 2-piece Pic rail and rings)
* New scope - Nightforce NX8 4-32x50 F1 (Mil-Mil, new Nightforce rings)

Thank you.

You need to get that scope higher. High rings should work.

 

[Paper boy]

1.5" should work.