This might help. A pdf document is also attached.
(Photo 01 - Soule Sight)
A Soule type rear sight is adjusted in the following ways:
Adjustments are made by turning the windage knob on the base of the rear sight. It is built on a left-hand thread therefore; clockwise turns move the sight body to the left. Counterclockwise turns move the sight body to the right.
The windage knob features large and small index marks on the right side. Rotating the assembly from one large mark to the next results in 1/2 minute if angle adjustment. Moving from a large mark to the nearest small index mark provides 1/4 minute of angle adjustment. One entire revolution of the windage knob equals 2 1/2 minutes of angle.
Adjustments are made by turning the elevation knob on the top of the rear sight. Before making ANY vertical adjustments of the rear sight, be sure to loosen the sight disks 1/2 turn. Failure to do so will result in damage to the sight.
The rear sight ladder or staff is indexed in increments of 5 minutes of angle. The elevator is indexed in increments of 1 minute of angle. Note how the smaller index marks on the elevator do not align themselves with any index mark on the staff at this point.
In the example the elevator is set to the “25” index mark
(see photo "figure A)".
To move the elevator up one minute of angle (to “26”), turn the elevation knob clockwise until the first small index mark on the elevator aligns with the “30” index mark on the staff
(see photo "figure B)".
To continue an additional minute of angle (to “27”), turn the elevation knob until the second small index mark on the elevator aligns with the “35” index mark on the staff
(see photo "figure C)".
To continue in increments of one minute of angle, continue the adjustment procedure as explained, always aligning the next index mark on the elevator with the very next index mark on the staff.
When a full five minute cycle of angle has been finished the first line on the elevator will align with the next 5 minute mark on the staff. (In this example, the “30” index mark.)
What are minutes of angle?
The term "minute-of-angle" (MOA) is used regularly by target shooters at the range, but is probably understood, thoroughly, by few. Defined loosely, one MOA = 1" at 100 yards; so, if you shot your rifle 5 times into a 100-yard target and every shot went into a one-inch circle you had drawn on the paper, then your rifle could be said to shoot 1 MOA. Likewise, if every shot goes into a two-inch circle at 200 yards, then you're shooting 1 MOA. A 10-inch group at 500 yards would be 2 MOA.
Is 1 MOA actually 1" at 100 yards? It is actually 1.047197580733 inches at 100 yards. Apparently, it is just a coincidence that 1 MOA happens to be REALLY close to 1" at 100 yards. It is, however, quite convenient.
The advantage in using a sight calibrated in minutes if angle is simple. It makes absolutely no difference what firearm the sight is mounted on; it can be easily and repeatedly adjusted no matter what caliber you are shooting. If you are hitting 2” low at 100 yards you will move you sight 2 MOA up and you’ll be at point of aim.
The other advantage of MOA is in further distances. If you know your ballistics for your chosen round, you can be pretty accurate in setting you sights for longer distances. For example, if you are sighted in at 100 yards and want to shoot at 500 yards, here is what you can do. Look at your ballistic chart. At 100 yards, note the height above the sight plane that the bullet is for a 500 yard impact. If it’s 45 inches, move your sight up 45 MOA and you’ll be in the ballpark.