Author Topic: HAM BC Database Adds SD & FF  (Read 331 times)


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HAM BC Database Adds SD & FF
« on: June 11, 2018, 08:33:49 AM »
If all those acronyms didn't get your attention, nothing will !!!!

At my suggestion, the excellent Hard Air Magazine database of Ballistics Coefficients has added two columns, containing the Sectional Density and the Form Factor of all the pellets they have tested.... Their testing was done with one LabRadar doppler chronograph, and all pellets were tested with the same gun (interchangeable barrels) at the same location (altitude), to eliminate as many variables as possible, and are calculated using the "GA" drag model, which is currently the best available for airgun pellets.... Adding the SD allows comparison between different calibers, and the FF allows you to gauge how "slippery" the pellet design is, with round nose pellets having a lower FF (and hence less drag) than wadcutters, for example.... There is a more detailed description of what these factors mean, and how they related to the BC and penetration on the introductory page to the database, which you can find here....

My thanks to Stephen for adding this valuable data.... As far as I know, it is the only pellet database which displays all these numbers, and you can sort it by each column in ascending or descending order (within each caliber), for added functionality.... I will be joining the HAM team shortly with articles of a technical nature, I hope you will find them enjoyable and educational....

« Last Edit: June 11, 2018, 08:36:30 AM by rsterne »

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Re: HAM BC Database Adds SD & FF
« Reply #1 on: June 11, 2018, 09:56:10 AM »
That is awesome!
Bob, you are one of those people who's positive impact on the airgun community can't be measured.

We are all fortunate that you enjoy sharing your knowledge and experience. And that you are patient and explain things so clearly and thoroughly.

Thank you!
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