How to Zero your Scope - "2 Shot System"
How to Zero your Iron Sights
A zero is the alignment of the sights with the bore of the
rifle so the bullet will impact on the target at the desired point of aim. When
the aim, the sights, and the bore coincide on the same point, it is called the
zero. There are two zero ranges, near and actual. These are the two locations
that the bullet crosses the line of sight.
Step 1: Determine your Zero Distance: 50 Meters
Firing ranges should have known distances marked by stakes, signs or lines on
the ground. Be sure to note whether it is yards or meters. While the difference
between yards and meters is relatively small, knowing it may save you some
ammunition.
If you are using a range that is not marked, you'll have to pace, measure or
laser range find the distance yourself. In this example it's 50 Meters.
Step 2: Fire 3 Round Group.
We are looking for a good tight shot group. Adjustments are made from an
estimated center of the shot group.
Step 3: Measure for Vertical Correction
Step 4: Measure for Horizontal Correction
MOA Defined:
A minute of angle (MOA) is an angular
measurement equal to 1/60 of 1 degree of arc. Its size increases uniformly over
the range, but its value stays the same. At 100 meters the true value of an MOA
equals 1.14 inches this can be rounded down to just one inch; one MOA at 200
meters equals 2.29 inches but can be rounded down to 2 inches; and at 300
yards, three inches; and so on.
Thus a sight adjustment error of 2 inches at
100 yards becomes a 10 inch error at 500 yards and a 20 inch error at 1000
yards.
Step 5: Look up your inch or
centimeter value for
your MOA/CLICK at your zero distance(Meters)
Step 6: Adjust elevation
settings
Number of clicks of elevation = Measure
of Vertical Correction Needed ÷ Inch or CM
for your MOA/Click at your zero distance
Example: 5.125 ÷ .57 =
8.99 round to 9 clicks up.
Step 7: Adjust windage
settings
Number of clicks of windage = Measure of
Horizontal Correction Needed ÷ Inch or CM
for your MOA/Click at your zero distance
Example: 3.25 ÷ .57 = 5.70 round up to 6
clicks to the left.
Step 8: Repeat steps 3-8 until your shot group coincides with your
point of aim
If it takes more time then do it. Better to be spot on then miss opportunities at greater distances.
Your graphic in Step 5 says to look up your MOA/Click at the zero distance. My question is, is that number consistent for all caliber and weights of bullets as it is shown in the chart in Step 5 or is it ammo specific. If it is ammo specific how do I find that info for the specific ammo I want to use ?
EdN. August 6, 2017 11:46 PM
Ammo specific. You can generally find ballistic profiles on ammo mfgr websites for your particular ammo. At moderate ranges you’ll be close, but longer shots will vary a lot. Document your zeros for each type ammo you have and correct your turrets accordingly. Then shoot to confirm.
Jama February 11, 2021 2:38 PM
This zero method is consistent with the particular ballistic profile for the ammo used during adjustment. Another type ammo with a different ballistic profile i.e. different projectile weight, powder load, shape, etc. will have to be accounted for and adjusted. Also, the shooting conditions , wind, relative elevation of target are assumed to be the same for zero and will need to be compensated for on the fly for every shot.
Jama February 11, 2021 2:28 PM