Pellet BC chart

[Franklink]

The app is called "easyBC"

Mr. Please share with us where you get this app. And do you feel strelok pro is the same calculation?

The app is called EasyBC and is found on google play, (and probably apple whatever). EasyBC is a free app.

Surprisingly, their is very little variance in BCs produced when the two speeds are plugged into any of the numerous apps and online calculators. Some of them don't even ask for altitude and yet, still produce fairly similar BCs for the same speed values. And for high BC pellets, the difference of the calculated BC has very little difference when using GA or G1 drag profiles.

 

[MartinT]

Atmospheric pressure has a great influence on drag. @Franklink: In your EasyBC you have it set at 970mbar. That is a pretty low value, so your location must be up in elevation quite a bit.
If you input the data from someone else, but that data is gathered at say sealevel (where the standard atmospheric pressure is 29.92inHg = 1013.25mbar (or hectopascal as we call nowadays) you will get a very skewed BC…

 

[Franklink]

Atmospheric pressure has a great influence on drag. @Franklink: In your EasyBC you have it set at 970mbar. That is a pretty low value, so your location must be up in elevation quite a bit.
If you input the data from someone else, but that data is gathered at say sealevel (where the standard atmospheric pressure is 29.92inHg = 1013.25mbar (or hectopascal as we call nowadays) you will get a very skewed BC…

I live at high elevation. If I adjust the values for my elevation than the apps spit out a lower BC and then the impact points don't match actual trajectory at my elevation.

If I use the elevated BCs, gathered from collecting downrange speeds at my elevation, and use that value in the ballistics apps then the actual trajectory at my elevation matches the predicted trajectory in the ballistics apps.

The various apps input for elevation (when it's even an option in that app) doesn't mirror actual as well as we'd all like it to. From the BCs that have collected for my guns at my home elevation, and then being able to go out and put pellets/slugs on prairie dogs with that information out to 200yards....my collected BCs are too high for nearly everything I've seen online (often from folks thousands of feet lower) , but actual trajectory matches those elevated BCs. So all I can conclude is that the apps inputs for elevation are less than accurate.

I'm with ya on the fact that atmospheric pressure has a massive effect. The point I'm making is that that apps BCs don't match my actual BCs, when I use the elevation function. I'm other words, if I adjust for elevation in the ballistics apps, then I get underestimated BCs that no longer match my actual trajectory.


The best way I've found to assess whether or not a calculated BC is accurate, is to shoot at various distances to figure out the actual trajectory at the elevation at which the downrange speeds were collected. If the BC calculated trajectory matches the actual trajectory....bingo, accurate BC. But yes, the downrange speed versus muzzle speed and subsequent real-world trajectory mapping all needs done for an individuals home elevation to be truly useable data for that individual. Ie, the numbers I ran for the original poster 16 months ago would all need verified by him at his elevation to be very useful to him.

 

[VneMC2]

The problem with making a BC chart from numerous sources is that you often have no idea how the test was fired, at what speed, under what atmospheric conditions, what reference drag law was used or what method was used to calculate the BC value. All of these factors can have a big effect on the resulting BC, particularly if the wrong reference drag law is used or the wrong calculation method. It is rare for testers to measure the atmospheric conditions during the tests, so the reported figures can vary widely from each other, leading to myths regarding pellet BCs.

The HAM figures claim to have been obtained under measured conditions using consistent reference drag laws, but there have still been some question marks on their figures.

even the smallest deformation of the exterior of a pellet will change the bc for calculation of very long distance shoopting

 

[SilentSquirrel]

The app is called "easyBC"


The app is called EasyBC and is found on google play, (and probably apple whatever). EasyBC is a free app.

Surprisingly, their is very little variance in BCs produced when the two speeds are plugged into any of the numerous apps and online calculators. Some of them don't even ask for altitude and yet, still produce fairly similar BCs for the same speed values. And for high BC pellets, the difference of the calculated BC has very little difference when using GA or G1 drag profiles.

FWIW
EasyBC does not show up in the Apple Store

 

[Franklink]

FWIW
EasyBC does not show up in the Apple Store

Bummer, sweet app. Reason # 797 that you should switch to Android

 

[JungleShooter]

Bummer, sweet app. Reason # 797 that you should switch to Android

And that a person with as much experience as Cole/ Franklink tells you this, well... — I'd count that as reason # 798....


I'm the last bastion in my family.
The rest has all bitten into the forbidden fruit....

Matthias

 

[Franklink]

And that a person with as much experience as Cole/ Franklink tells you this, well... — I'd count that as reason # 798....


I'm the last bastion in my family.
The rest has all bitten into the forbidden fruit....

Matthias

Lol, a guy at work call em CrApple.

For the whole world, Android vs Apple is like Daystate/BRK versus FX is here on the forum. "Them's fighting words." Which words you ask? ALL THE WORDS when it comes to anything Apple vs Android or Daystate/BRK versus FX. Ha ha