Which Hornady Bc to use?

[BrentH]

Trying to get my ballistic solver setup for my 6.5 Creed shooting the 143 ELD-X.

New Hornady Published Data:

Mach 2.25
G1: 0.623
G7: 0.314

Mach 2.0
G1: 0.604
G7: 0.303

Mach 1.75
G1: 0.584
G7: 0.294

The Hornady App and the GeoBallistics app appear to be using the Hornady Published “Mach 2.25” G1/G7 values.

The Sig BDX app (I am using a Sig 8k) is using different values, G1: 0.571, G7: 0.292

I had planned to plug in the G7 value, but which one should I use?

Caveat: I would like to shoot rocks out to 1k, but shots on animals would be sub-500, so maybe it doesn’t matter? I will be using MV as collected from my Magneto.

 

[BrentH]

Which solver? Modern solvers will typically be using a doppler file, or at a minimum they should be using a step function for G1/G7 based on down range velocity, and 143 ELDX is so popular it should be in their library. In 2023, I wouldn't take a solver seriously that you have to manually input that data - there's too many other quality solvers on the market.

-I use custom curves with AB (and that's what I'd recommend), but their G7 is 0.292 for 143 ELDX. Your Sig should be running an AB product.
-If you're using 4DoF (which is free), use their doppler file (the actual 4DoF) instead of their "standard" G1/G7 solver.
-If you're using Revic (which is free), use their doppler files instead of a G1/G7 solver.

If you haven't already, look at your down range remaining velocity/Mach #, and ToF at 100 yard intervals. You can also toggle the BC and look at the change in predicted solution at various ranges to get a better feel of what's important.

For whatever it's worth, based on my elevation, and the MV I've had with 143 ELDX, if I integrated the basic step function G7 for 1,000 yards, I'd get a BC of ~0.298. But again, I'd focus on using a quality modern solver that provides doppler file data.

Yes, I am running the Sig App/Solver, which I believe is based on AB.

When it was popping up with the option of G1, G7, and Custom, I was choosing G7 and was confused by the value being displayed not matching any of the other published data. Sounds like maybe the better option would be to select the custom curves and be done with it?