Hornady 4DOF ZERO Angle

[sawateam]

Couple questions on Hornady’s Zero Angle…

I’m using the Measure Impact Location feature in the app and a picture of a 14 shot group. It was shot at 100yds indoor so i left the wind values at zero.

Typically when i zero this gun my 3-5 shot groups are less than 1/2 MOA. This 14 shot group (pics attached) widened out to about .9 MOA.

I think I saw in one of their videos that it’s OK not to float and zero the turrets after performing the group analysis because the app knows where your POA was in relation to your impacts. Is this the case cause it’s messing with my head?

 

[Baron23]

@Ledzep

 

[OREGUN]

No “zeroing” required. The zero angle will correct for your average group center being .22” left and .22” down. Of course, if you want to to come up and right with your dials, you can and then either shoot another group (five shots should be plenty) and tell the zero angle calculator about the new average group center. Or, if you wanted to, you could adjust the turrets and then just correct the data fed to the zero angle calculator without shooting the group (come up and right 1/4 moa and then tell the app that your average group center is .03” right and .03” high) All the ways will result in something fairly close.

 

[Ledzep]

When you use "Zero Range", you tell the app that you are perfectly zeroed at 100yd (or whatever distance you put in). This forces the solution to cross elevation= 0 at whatever distance you put in. Simple enough. However, most of the time, if you were to lay down and shoot at 100yd, you would not hit EXACTLY at 0 elevation. You'd be .05" high or whatever. So that .05" (or whatever it is) is an error, and that error carries throughout the trajectory.

Zero angle takes into account the environmental conditions at the time of zero, the MV, sight over bore, and impact location (average point of impact) and back-calculates the ONLY way that could happen as an angle between the muzzle-exit-vector of your bullet and your optic. Zero angle is the angle between the direction your bullet exits the muzzle and your optic cross hair at "0" in the vertical plane.

So in the process of setting up a zero angle, it will ask you for all of the environmental conditions, the height of your scope over the bore, MV, twist rate, etc... and most importantly the distance and MPOI impact location. All you have to do is tell the app where you hit (MPOI) and what distance and it will do the math to generate what the muzzle exit vs. optic zero angle had to be. (0.06-0.09 degrees usually).

 

[Ledzep]

Based off of your target, here's the inputs in 4dof to find your zero angle. The rest of the stuff above this is unique to your load/rifle and I have generic sea level environment.

 

[Ledzep]

After you do that, you can verify by putting in 100yd, no wind and see what correction it tells you. In this case it says to impact perfectly dead center you need .06 mils (.22" at 100yd) up and right. So this minor deviation in 100yd "zero" will carry through in every down-range calculation you use with this file.

 

[4O6shootist]

Can this info be sent into a 4dof kestrel and used in solution? 4dof kestrel doesn't allow your zero offset at 100y like AB does.

 

[Ledzep]

I'll have to double check but I'm pretty certain you can use ZA in the 4DoF Kestrel. It is often easier to figure out what the value is in the app, then feed the info through Kestrel Link.