Misaligned scope

[olddav]

OK, I have a question.
I installed a scope on to my rifle and sighted it in at 100 yards. My first shots hit 14" to the left. I was able to adjust the POI with one full turn of the windage knob (approx), but this left me felling a bit disappointed.
Using a website that calculates triangles and I believe that the scope is misaligned by .239 degrees. My question is how much do I need to move the scope to bring it inline with the barrel (measured in .000 of an inch). Since this is not a new problem I'm betting someone has done the math before, at least I hope so.

I know there are lots of products out there for this very issue but I'm not interested in those (although others may be) as I'm looking for specific information.

 

[Turbulent Turtle]

There was no need for a website to calculate triangles. If your shots are off by 14 inches at 100 yards, that's analogous to 14MOA. Since there are 60 minutes in an angle, you take 14 and divide by 60 and the answer is .2333 degrees off.

Now, if you want to correct that, you will need to move the front ring one way or the rear ring the other way. Either way, you will need to move the ring for a specific value which depends on the distance between the front ring and the rear ring.

Let's say the distance between the two ring (center to center) is 4 inches. You will need to move the front ring or rear ring by about 0.016 inch. If it's the front ring you will need to move it in the direction of the impacts on target and if it's the rear ring, you need to move the ring in the other direction.

Your best bet is to use Burris Signature rings and use the proper inserts, placed vertically to cure the problem.

 

[olddav]

Turbulent Turtle,
Thanks for the info, but what formula did you use to determine the correction at 4" ring spacing?

 

[olddav]

I think I figured it out but please post the formula for conformation.

 

[BoydAllen]

14/3600 = x/4
Solve for X

 

[rammac]

Or, using trig for a triangle:

TOA

Tangent of the angle = the length of the opposite side divided by the length of the adjacent side and solve the equation for the length of the opposite side.

O= TA

O= Tangent (.233)x4
O=0.00407x4
O= .016"

 

[Centuriator]

To the OP: if your shots were 14" off...get on YouTube and study carefully how to get a scope properly mounted and sighted in. It's not really that hard. You can do it.

 

[olddav]

Thanks to everyone!
I am able look smarter outside of this forum by confessing my limitations and asking for help, and y'all are kind enough to provide it.

Thanks again to everyone!

 

[Turbulent Turtle]

Turbulent Turtle,
Thanks for the info, but what formula did you use to determine the correction at 4" ring spacing?

Sorry, got busy at work. Rammac got it right the first time.

 

[Brians356]

14/3600 = x/4
Solve for X

There's a good reason they teach geometry earlier than trigonometry. KISS.
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