Near Zero and Far Zero

[Stoopy]

There's a neat trick I teach on how to fully use that dope sheet.
Print out a fresh one for EVERY DAY you go to the range.
Gather hard dope at known distances, keeping track of the temperature when you gathered the dope.
Now look at my sheet and go across at each distance you have hard dope for and CIRCLE the hard dope number.
Some form of line will get plotted.
As long as the temperature stays the same, work within the line that's plotted.
As the temperature changes, move right (hotter) or left (cooler) from the plotted line.
This system works VERY well and I have the trophies to prove it...

Hey Randall, could you help me with this at the match? The way the numbers are arranged is confusing me.

[AR15barrels]

Hey Randall, could you help me with this at the match? The way the numbers are arranged is confusing me.

The numbers are arranged in pairs, the top number of a pair is elevation and the bottom number is windage.
Then the temperatures are along the top.
This is all based around a 60degree 2500ft DA zero which will be very close at angeles.

[Stoopy]

The numbers are arranged in pairs, the top number of a pair is elevation and the bottom number is windage.
Then the temperatures are along the top.
This is all based around a 60degree 2500ft DA zero which will be very close at angeles.

yeah, but the drop from your zero at 50 yards to 15 yards is confusing me. Wouldn't those be negative?

[AR15barrels]

yeah, but the drop from your zero at 50 yards to 15 yards is confusing me. Wouldn't those be negative?

No.
You dial MORE elevation to get on target at shorter ranges.

[Stoopy]

No.
You dial MORE elevation to get on target at shorter ranges.

because the scope is above the barrel and the trajectory of the bullet crosses above the center line of the scope with a 50 yard zero?

[GforceJunkie]

...because your hitting the target on your bullets way up, the first crossing of the line of site. Check out this pic, if the target is your 50 yard zero, with a .22 it is also pretty close to zero also at about 20 yards. Notice that the bullet is below the line of site from the muzzle to about 20 yard. So to dial for those distance you have to dial up.

No.
You dial MORE elevation to get on target at shorter ranges.

[Stoopy]

Ok, I understand it now. I never shot my .22 less than 50 yards so I never thought about having to dial up for close shots. Thanks guys.

[GforceJunkie]

It get tricky when you start using the first and second "zero" to make hits. You need to keep a visual of that pic in you head as to what the bullet is doing. Notice on the dope chart that all the distances between 20 and 50 yards are positive, thats because thats the time the bullet is above the line of site. Whenever the bullet is below, the dope corrections show it as a minus correcton since you have to come up. The good news with such short range shots is if your dope is off on the first shot, its simple to just hold the correction for the following shots. Thats why some sort of milling reticle is handy.

[AR15barrels]

Ok, I understand it now. I never shot my .22 less than 50 yards so I never thought about having to dial up for close shots. Thanks guys.

As you can see on the illustration above, there are TWO ranges where the bullet crosses the line of sight.
I call these points the "near zero"and "far zero".
On a 22 using target ammo with a 50yd far zero, the near zero is around 18yds.
We normally work from our "far zero" out and in that situation, we keep pointing the barrel up more and more so that it will land on the target where we are aiming with the scope.
When you shoot WITHIN these two zeros, you can EITHER dial up or down.
it's a smaller amount of dial to dial backwards so that's what my chart shows.
Where it gets tricky is when you get SHORTER than the near zero.
THEN you have to dial MORE elevation again to point the barre up more to get the bullet to impact the target.