Ballistics calculator drops off after 500 yards

[TimeOnTarget]

Hey Guys,

I've been absent from the site for awhile but have come across something i cannot seem to resolve.

I'm shooting a custom 6.5x284 1-8" twist using a 143eldx at 2998fps verified by my magnetospeed. Optic is a vortex Razor Gen II 4.5-27moa.

I'm using the hornady DOF4 ballistic calculator. I've checked my inputs over and over again and cannot find one that is wrong.

Now for my problem, my drops out to 500yds seem spot on 500yds calls for 6.98moa of come up which rings the gong center mass everytime, my next gong is at 700yds, which calls for 12.52moa of come up, in reality i need 11.5-11.75 MOA of come up to hit center mass.

What is coming into play here between 500yds and 700 yds?

 

[coop2564]

Your speed is most likely faster than your reading likely 3050 by my calculations.

 

[TimeOnTarget]

Your speed is most likely faster than your reading likely 3050 by my calculations.

And you're thinking its just not noticeable at the shorter distances?

 

[Canhunter35]

What are you using to calculate your environmental inputs?
I agree, probably ur mv,
Check it at 600 also, more distances will allow you to validate the curve better

 

[ShtrRdy]

What does the terrain look like? Are you shooting over flat ground, or is there a valley/ dip? Are there trees or other obstacles on either side of the path the bullet is traveling?

 

[TimeOnTarget]

What are you using to calculate your environmental inputs?
I agree, probably ur mv,
Check it at 600 also, more distances will allow you to validate the curve better

I've got a kestrel and a weather flow wind meter. Thats where my inputs come from. Both the weather flow and kestrel correlate with each other.

 

[TimeOnTarget]

What does the terrain look like? Are you shooting over flat ground, or is there a valley/ dip? Are there trees or other obstacles on either side of the path the bullet is traveling?

Terrain is generally flat, living in South Dakota, there may be 10ft of total elevation change between zero and 700yds.

 

[tuscan]

In addition to the terrain question, can you tell us the elevation of your range? You've undoubtedly put that into your ballistics calculator, but in my experience, differences between ballistics calculators grow at high elevations.

 

[TimeOnTarget]

In addition to the terrain question, can you tell us the elevation of your range? You've undoubtedly put that into your ballistics calculator, but in my experience, differences between ballistics calculators grow at high elevations.

1300' is all.

 

[coop2564]

I lot of apps have Drop verification in them for small velocity errors like this to correct out your velocity. I'm guessing the one you are using might not. But mine shows you should plug in about 3050 for the data you have giving us.

 

[TimeOnTarget]

i dont believe hornady has that feature. I'll give 3050 a shot.

The only other thing i could think of is if my scope is not tracking correctly.

 

[Canhunter35]

i dont believe hornady has that feature. I'll give 3050 a shot.

The only other thing i could think of is if my scope is not tracking correctly.

Jbm offers mv truing as does applied ballistics on my kestrel.
If you're worried about ur scopes tracking do a tall target test

 

[westcliffe01]

At what distance is your zero ? A small error at 100 yards will show up at longer distances. You should always verify elevation at an intermediate distance 300-500 yards. Beyond that, verify G7 coeficient and adjust velocity.

 

[bigngreen]

I find checking your zero at 300 tells you if your 100 yard zero is correct and I almost always do a little tune to my zero. By 300 velocity and BC are not making that much difference so when your of it's usually zero hight. Tracking will show up very similar to velocity with the dial up progressively growing with range.