Help! New Scope ran out of up adjustment!

H

Hydrostatic Shock

New member
So I'm trying to replace a POS tasco with a Nikon 6-18x40 mildot from midway USA. I believe the scope only has 40 MOA of adjustment.

So I get it all set up and try to bore sight it. It ran out of up adjustment and the bore sighter shows it to still be 16 inches high with the turret maxed out. This was confirmed by looking through the bore and comparing the cross hares.

I even tried 3 coke can shims and it still bore sighted 4 inches from zero maxed out.

The gun is a rem 700 7mag with standard 2 piece leopold mounts and medium rings.

Anyone had this problem with this scope? Could the scope be out of spec? Any ideas would be appreciated!

Actually it's my brothers gun I was just helping him put it on.
 
The scope you have chosen is a good one. You should not be having these kinds of problems.

Let's get back to basics.

Are you using a laser boresighter or are you actually looking through the bore?

What is the distance? If your distance is too close, you will never get your elevation to agree with what you see through the bore.

Is the mount on the rifle "special" in any way? Does it have an angle built in it to allow for extremely long range shooting?

When you installed the scope in the mounts, is there any chance you tweaked the tube?

Take your elevation knob and run it to the stops. Either up or down. Do not force the knob.

Now take the knob and turn it ALL the way opposite of what you just did and count the number of turns. Again, do not force.

Once you have counted the number of turns, divide by two and turn the elevation knob back in the opposite direction THAT number of turns.

You should now have your elevation mechanical zero.

Try your boresighting again.

Another experiment if you are using a laser boresighter, is to insert the bore sight and compare what you see relative to the cross hair and then remove and reinsert the boresighter and see if the picture is the same.

I have had similar problems boresighting my M1A when I had the distance too close and could not dial the elevation in.

I moved the distance out to the garage door on the house across the street and found there was plenty of adjustment to bring the elevation in.

It has been my experience that it is usually, not always, but usually something very basic and simple that throws you for a loop.

I have a number of Nikon scopes and they are quality products. It is POSSIBLE to get a defective one, but I am betting it is something simple.

Go back to the basics of checking screw tightness and re-establish your mechanical zero for elevation. Might even do to establish mechanical zero for windage.

Get back with us and let us know what happens.

Geetarman:D
 
But before you buy the MOA rail reverse your rings. I couldn't see any physical difference in mine but when I put the front in in the rear and the back one up front suddenly I was a couple of inches from zero with the scope adjustments centered. Maybe I adjusted the screw tension differently or held my face different or it was black magic, I don't know but it was simple and it worked, It will only take a few minutes at no cost to try it.
 
I know Ruger sells rings for their M77 rifles where the heights are different.

I really do not know about other manufacturers. It is certainly worth a try.

Geetarman:D
 
Like geetarman said, I think you are trying to zero too close in. Discard the "boresighter", set the elevation and windage knobs to nominal travel, move to the 100 yd. range and zero by observing the point of impact on your target.
 
My brother called Nikons customer support and they said the scope was likely defective since the tasco would sight in. They told him to send it back. Midway has told him they will replace it so he sent it off today.

I'll update when we get the new one in and let yall know what happened. If it's the same thing we are going to try to reverse the rings. They are dual dovetail leopold with 2 piece bases. The bases won't reverse due to the design of the receiver.

Thanks for the input and I'll update in a few days.
 
just taking a stab at this one, but if memory serves me right, one base is flat on the bottom, the other is rounded.....so I don't think he has the bases switched. At least on the newer 700's they are.
 
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