Hornady ballistics

[JoeInTucson]

I have been looking at the variable BC numbers for Hornady match bullets.
I dont always know which one to use, what do you guys think about this?

 

[SKWERLZ]

You just have to try them.
If they work for you,,,,great.

 

[jelenko]

variable BC numbers

How do you mean 'variable'?

 

[LVLAaron]

How do you mean 'variable'?

BC depends on the velocity

 

[RegionRat]

When there is user-based radar track data or "custom drag models" available for a given bullet on Applied Ballistics, I like to compare all of the available BC values and the final judgment is based on which one is closer to the resultant drops I get at distance.

They often take data for folks at well attended matches. When lots of folks run a given bullet, eventually the data gets lumped together into a pretty good estimate based on lots of different barrels and twists.

 

[ELR LVR]

I have been looking at the variable BC numbers for Hornady match bullets.
I dont always know which one to use, what do you guys think about this?

If you can find the G7 number it should be a litle more accurate for your DOPE chart.
G1 will get you close but you must shoot it and true the number
Best to always create your own DOPE chart regardless of any advertised numbers
(Don't trust anyone but yourself when it comes to guns)
Shoot the bullet at 3 different varying distances, then create your chart
since it can be a conincidence if it coincides at just one distance
I've had my numbers right and correspond for 600 yds but then had elevation be a bit off for say - 1200 yds.
Which then means I can only use my chart for 1 distance which is not very useful

 

[JoeInTucson]

How do you mean 'variable'?

They list 3 different BC numbers depending on the range you are shooting at.

 

[FeMan]

Hornady publishes variable BC values for their ELDM bullets which is based on velocity. I think their intent is that you use the BC that best matches the average velocity of your bullet over the distance being fired.

Their highest recommend BC values are intended for shorter range shooting where average velocities are above 2,500 fps (distances out to 300 yards according to their website). They recommend the middle BC values for mid-range shooting where velocities average 2232 fps. They recommend using the lower BC values for long range in cases where the average velocity is 1953 fps or less.

Drag on a bullet increases with velocity and the G7 (and G1) curves reflect that. What Hornady seems to be saying with the substitution of higher BCs with higher velocity is their bullets do not follow the G7 curve and are actually more aerodynamic. I have never experienced this and have had the best results using their lower G7 BC values at all distances.

 

[WSnyder]

I have been looking at the variable BC numbers for Hornady match bullets.
I dont always know which one to use, what do you guys think about this?

They list 3 different BC numbers depending on the range you are shooting at.

Many ballistic apps like Shooter allow you to enter all of the listed BC's with the corresponding velocity ranges which could possibly provide better results overall. Sierra provides the same. The individual BC's are not meant to be entered as an individual number for a specific range but meant to be entered as I described.

For example: