Rifle Scopes Question about fine tuning scope alignment

[DOC_2009]

I shoot a 20" rem 700 with a leupold mark 4 4.5-14x50. Mounts are EGW one piece rail and Burris XTR rings (saving up for some Badger stuff). I leveled scope using set of feeler gauges between flat bottom of scope and the rail. Ive noticed that on completely calm days, a perfect zero at 100yds shoots around 4 inches right at 400. If my thinking is correct, that means the scope is rotated a little clockwise and would require rotating counterclockwise a bit to be perfectly level. Does anyone know any tricks for doing this as in determining how much to rotate?

Thanks,
DOC

 

[dieselten]

Re: Question about fine tuning scope alignment

If you leveled it with feeler gages then your off set is probably the base. The holes in the receiver are not perfectly on center which allows the base to be mounted slightly off. Your scope windage will easily compensate for this but it will add windage error as the range is increased. If you can find true center for windage on your scope and see how far you had to adjust windage from there to get the rifle to zero at 100 yards, then you will get the idea.

 

[Rafael]

Re: Question about fine tuning scope alignment

It may be the scope or it may be you.

Are you sure the reticle is square with the scope body?
Are you sure you are holding the reticle straight when you are shooting?
If you are dialing elevation, are you sure the scope tracks square to the reticle?

The feeler guage method should work fine if the reticle was installed square to the scope body.

I prefer to align mine by clamping the rifle in a vise with the base being level....assuming the base is perfectly perpendicular to the bore. I align the reticle with a distant known-plumb surface; in this case it is a corner of amy neighbors house.
I tighten the rings leaving it aligned in this manner. Then I crank the elevation all the way up and down; checking to make sure the reticle is not walking off the vertical plane of the "target" object. This verifies that the scopes elevation tracks correctly.

After that, I prefer to use a level when I shoot. I make sure my level was zeroed with the reticle when I installed the scope in the rings.

Right or wrong... thats how I like it done on my weapons.

 

[Rarebreed93]

Re: Question about fine tuning scope alignment

Doc, check out this video, might be just what the Dr. ordered;
http://vimeo.com/13563013

 

[DOC_2009]

Re: Question about fine tuning scope alignment

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: dieselten</div><div class="ubbcode-body">If you leveled it with feeler gages then your off set is probably the base. The holes in the receiver are not perfectly on center which allows the base to be mounted slightly off. Your scope windage will easily compensate for this but it will add windage error as the range is increased. If you can find true center for windage on your scope and see how far you had to adjust windage from there to get the rifle to zero at 100 yards, then you will get the idea. </div></div>

So would windage adjustable rings fix the problem? If so, which ones do you guys recommend?

Thanks, DOC

 

[dieselten]

Re: Question about fine tuning scope alignment

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: DOC_2009</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: dieselten</div><div class="ubbcode-body">If you leveled it with feeler gages then your off set is probably the base. The holes in the receiver are not perfectly on center which allows the base to be mounted slightly off. Your scope windage will easily compensate for this but it will add windage error as the range is increased. If you can find true center for windage on your scope and see how far you had to adjust windage from there to get the rifle to zero at 100 yards, then you will get the idea. </div></div>

So would windage adjustable rings fix the problem? If so, which ones do you guys recommend?

Thanks, DOC </div></div>

In most cases...yes.

USO makes a nice set. You could also try those Burris rings that use the off set inserts.

 

[CoryT]

Re: Question about fine tuning scope alignment

No, windage adjustable rings will not fix an out of level condition.

First, let's estabilsh what the problem actually is. With the rifle in a vise or firmly sandbagged in position on the 100 yard line, align the reticle on a target at the top of a sheet of cardboard at least 30" in length. Make sure the RIFLE is level, don't align the crosshair, use a level on the receiver, or a plumb line through the center of the butt.

Now, dial 25 MOA up, Drop a plumb line from the original point of aim. If the center of the crosshair is not on that line, then it does not track vertical and will need to be aligned.

Make a fine pencil mark on the tube and a ring to show the current alignment. Loosen the scope ring caps just enough to rotate the scope. If you are right of the line, rotate clockwise just a bit, snug the screws back up a bit, dial back to zero and repeat the above test. Continue making small adjustments until the crosshair tracks the plumb line.

Now, if the base was not actually level, the scope is, so you are good to go. If the crosshair does not appear level when the rifle is level, the crosshair is not square to the erector assembly, the scope will need to be sent back for repair.

 

[dieselten]

Re: Question about fine tuning scope alignment

If the base mount holes were drilled off center, within reason, this can be corrected to a serviceable condition with windage adjustable rings and subsequent re-leveling of the scope/reticle..

 

[Rafael]

Re: Question about fine tuning scope alignment

You are missing the point Cory and I have made.
If he were off by 1 moa at both 100 and 400, and ran out of adjustment on windage, adjustable rings would help.
That is not the case he described.

His hold, or his reticle, or his scopes tracking are not plumb. This is what causes errors like the one described....unless he is missing a wind call.

New rings won't fix this issue.