Sight adjustment formulas

[French Colonial]

I am putting new sights on my old Jaeger to make them more user friendly for my aging eyesight and thought that the formulas for adjusting them may be of interest.

Easiest
Sight radius (distance between sights in inches) X distance to move impact on target in inches / divided by distance to target in inches = equals amount to move sight

distance to target
25 yards = 900 inches
50 yards = 1800 inches
100 yards = 3600 inches

example
Jaeger 20" sight to sight X 1" distance to move impact / 900 for 25 yards
20 X 1 / 900 = .0222222

Harder method, adjusting for MOA
For different distances if you know the Minutes of angle you want to move
Sight radius in inches X .000291 = 1 MOA

1 MOA =
50 yards =.5235987
100 yards = 1.0471975
200 yards = 2.09439

Example, my Virginia rifle with 37" sight radius is shooting 2" high at 50 yards
37" X .000291 = .010767
2" /yardage .5235987 = 3.73143378477

3.73143378477 X .010767 = .0401763 (distance to move)

Just throwing it out there if it helps anyone, just in case anyone takes dial calipers to the range

 

[Eric Krewson]

That is a lot of "figurin", too much for this former East Tennessee ridge running red neck from Norris TN. I just shoot them and adjust as needed, might take ten shots, usually 5 or 6 is enough, a little filing on the front and a little drifting on the rear.

 

[ohio ramrod]

I don't take calipers to the range, but I have modified a micrometer head to fit on the barrel. It is a simple "Z" block. One side fits on the flat of the barrel, the other is drilled-split -and tapped to hold the micrometer head. It makes adjusting sights much quicker if you know how much you actually move your sights.. I will shot a three to five shot group for each adjustment.If anyone is interested I will try to get a picture of the "Z" block and post it.

 

[SDSmlf]

I am putting new sights on my old Jaeger to make them more user friendly for my aging eyesight and thought that the formulas for adjusting them may be of interest.

Easiest
Sight radius (distance between sights in inches) X distance to move impact on target in inches / divided by distance to target in inches = equals amount to move sight

distance to target
25 yards = 900 inches
50 yards = 1800 inches
100 yards = 3600 inches

example
Jaeger 20" sight to sight X 1" distance to move impact / 900 for 25 yards
20 X 1 / 900 = .0222222

Harder method, adjusting for MOA
For different distances if you know the Minutes of angle you want to move
Sight radius in inches X .000291 = 1 MOA

1 MOA =
50 yards =.5235987
100 yards = 1.0471975
200 yards = 2.09439

Example, my Virginia rifle with 37" sight radius is shooting 2" high at 50 yards
37" X .000291 = .010767
2" /yardage .5235987 = 3.73143378477

3.73143378477 X .010767 = .0401763 (distance to move)

Just throwing it out there if it helps anyone, just in case anyone takes dial calipers to the range

Maybe compile data into a chart….. like many gunsight makers have already done. Might be easier. Here for example, is one published by Lyman.

 

[French Colonial]

I don't take calipers to the range, but I have modified a micrometer head to fit on the barrel. It is a simple "Z" block. One side fits on the flat of the barrel, the other is drilled-split -and tapped to hold the micrometer head. It makes adjusting sights much quicker if you know how much you actually move your sights.. I will shot a three to five shot group for each adjustment.If anyone is interested I will try to get a picture of the "Z" block and post it.

Yes, I would like to see the "Z" block

 

[French Colonial]

Maybe compile data into a chart….. like many gunsight makers have already done. Might be easier. Here for example, is one published by Lyman.
View attachment 88830

I like my formulas, good for different distances if you know the distance.
The chart is great and I will probably save it, but for, lets say 40 yards.....you can use the chart by converting it with a formula!

 

[SDSmlf]

I like my formulas, good for different distances if you know the distance.
The chart is great and I will probably save it, but for, lets say 40 yards.....you can use the chart by converting it with a formula!

Guess you could call using a multiplier a ‘formula’ if you want. Like calling it a formula to go from inches, to feet to yards….. At 40 yards you would multiply the chart number by .40, at 120 yards yards multiply by 1.2 and at 360 yards by 3.6.

 

[dave951]

When I'm working up a load in a gun I carry a set of dial calipers with me. Formula is saved in my cell phone. For those using the formula, remember to work in inches. Example, sight radius is in inches, so distance to target must also be in inches. 50yd is 1800in and 100yd is 3600in.

 

[Stantheman86]

It all depends on the type of sights.

If the rear sight is a fixed block sight I like it to have a 200 yard zero so I'm good for all the ranges I normally shoot at.

 

[Larry (Omaha)]

I am putting new sights on my old Jaeger to make them more user friendly for my aging eyesight and thought that the formulas for adjusting them may be of interest.

Easiest
Sight radius (distance between sights in inches) X distance to move impact on target in inches / divided by distance to target in inches = equals amount to move sight

distance to target
25 yards = 900 inches
50 yards = 1800 inches
100 yards = 3600 inches

example
Jaeger 20" sight to sight X 1" distance to move impact / 900 for 25 yards
20 X 1 / 900 = .0222222

Harder method, adjusting for MOA
For different distances if you know the Minutes of angle you want to move
Sight radius in inches X .000291 = 1 MOA

1 MOA =
50 yards =.5235987
100 yards = 1.0471975
200 yards = 2.09439

Example, my Virginia rifle with 37" sight radius is shooting 2" high at 50 yards
37" X .000291 = .010767
2" /yardage .5235987 = 3.73143378477

3.73143378477 X .010767 = .0401763 (distance to move)

Just throwing it out there if it helps anyone, just in case anyone takes dial calipers to the range

Sight Correction Calculator | Top Rated Supplier of Firearm Reloading Equipment, Supplies, and Tools - Colt

Check the link and you will get what I show below
https://www.muzzleloadingforum.com/...00$ContentPlaceHolderColMain$lnkAddLearnFav,)
Sight Correction Calculator
If you can’t adjust your elevation up or down enough to get the bullet on target, use the chart below to determine the amount of correction either positive or negative. Remember adding a higher front sight will bring the strike of the bullet down and using a shorter front sight will move the strike of the bullet up on the target.
Click here to use the Brownells Sight Correction Calculator.
Please make sure you have popups enabled and the
newest version of Adobe Flash Player installed.

 

[French Colonial]

When I'm working up a load in a gun I carry a set of dial calipers with me. Formula is saved in my cell phone. For those using the formula, remember to work in inches. Example, sight radius is in inches, so distance to target must also be in inches. 50yd is 1800in and 100yd is 3600in.

Yep, calipers! I also have a portable vise that has a rotating head with rubber inserts for the jaws.
Figure how much you need to move things, clamp the vise on to the bench, the gun in the vise and use a good file and get it filed down.
All done.

 

[ohio ramrod]

Here (I hope) is a picture of the Z block I made for adjusting sights.It holds a micrometer head so you can measure exactly how far you move your sights.

 

[French Colonial]

Here (I hope) is a picture of the Z block I made for adjusting sights.It holds a micrometer head so you can measure exactly how far you move your sights.

Yes, that makes sense. Thanks for the picture, I was having trouble imagining how it worked.
For some reason I assumed you were using it to actually push the sights but you are using it for measuring, which is a very good idea.

Calipers work very well on the front sight put can be a pain on the rear, your "Z" block solves that.