AB Zero Height/Offset and CDM (Garmin 701)

[021411]

Sorry to bring up another settings related post. I'm just going through the options and getting everything set on my Garmin 701. I think I'm clear on everything except for the height/offset feature and CDM.

I have a single caliber/barrel rifle and don't plan on switching. Is the height/offset option necessary?
What about this hypothetical scenario? I zeroed my rifle and no other adjustments are possible to get it to hit dead center. It's as close as it will get and zero stop it set. For the sake of discussion, the impact is 0.25" high and 0.25" to the right. At this point do I input values now? From what I've read on the 701, I would have to input (minus) 0.25 on the height and (minus) 0.25 on the offset. Correct?

Lastly CDM. I have it on the CDM but the ballistic coefficient is at 1.000. Is this correct indicating that the ACTUAL ballistic coefficient is hidden? No adjustments are necessary?

 

[Clearlight]

Regarding your zero offset , your actual zero is + 0.25 vert and + 0.25 for horizontal . Left offset is negative .
Regarding CDC , actual banded BC is proprietary in-house data . You get to use the curve via the solver ,
but the actual BC’s at any given fps / distance are not shown . It stops other PM solver companies from
stealing Applied Ballistics data for free .

A lot of other shooting related companies use ABs BCs anyhow , pretty sure most of them don’t have the
facility or large radar unit , and Ohler 88 required to generate data .

 

[021411]

The reason I put negative is that people found out here that on the 701 it’s reverse when putting inputs in.
And in my hypothetical case, do I input anything at all? That’s what I’m asking if I for some reason can’t 100% get dead center.

 

[aaronk]

Correct on the values to input on the 701, they are backwards until AB (hopefully) updates the firmware to correct this. In your hypothetical situation I would go ahead and enter the offset. The zero offset isn't just for shooting different loads, it can also be used exactly as you describe, in the event you can't get a dead center zero.

 

[_Windrider_]

The reason I put negative is that people found out here that on the 701 it’s reverse when putting inputs in.
And in my hypothetical case, do I input anything at all? That’s what I’m asking if I for some reason can’t 100% get dead center.

The offset calculates true range zero in the background. So if for example you zero at 100yds but what you call a good zero is 1” high and 3/4” right from POA, that’s not a 100 yard zero.

 

[021411]

Last question. Do I need to turn on spin drift and Coriolis? I’m shooting up to about 1000 yards.

 

[_Windrider_]

Last question. Do I need to turn on spin drift and Coriolis? I’m shooting up to about 1000 yards.

I’m not gonna answer this one. Some yes and some say no.

 

[021411]

I’m not gonna answer this one. Some yes and some say no.

Fair enough. I guess I can experiment.

 

[Darkhorse1]

The reason I put negative is that people found out here that on the 701 it’s reverse when putting inputs in.
And in my hypothetical case, do I input anything at all? That’s what I’m asking if I for some reason can’t 100% get dead center.

I just got a 701 recently, and am playing with these settings too. It definitely is backwards meaning a POI .25" high, and .25" right needs to be input as negative values to get the correct dope. This is a little annoying since my Ballistic AE app on my phone does it correctly, and where I keep my load data. In regards to your question, I'd think the zero height makes sense to correct (as long as it's a small correction) since everything would be correct beyond 100yds or whatever distance you originally zeroed the gun. Regarding the zero offset, I'm wondering if in your example, would you only need to adjust your windage turret to the 100yd call, and that would then work out to 1000 etc. as long as you put the wind speed at zero? So hypothetically if there was no wind, you could use that 100yd wind call correction on the turret and hit at 500 etc. just using the elevation calls/holds? This seems to be the case on both Ballistic AE and the 701 (both having spin drift and Coriolis off however), but haven't used this for anything before. In my case, I'd mainly be using it for unsuppressed/suppressed same load/bullet combo, but would be cool if it worked with different load/bullet in the same rig, and just adjust mv for the profile. I've already got an older Kestrel, so hoping to get this 701 dialed in.