AGN is proud to share HAM's BC database

Awesome! Thank you!

Thank you for SHARING!!!

Wonderful, thank you guys for hard working & sharing. 

What an excellent resource! Thanks much!

Great Resource thank you!!

Outstanding i read there article and i see it is not set in stone..im certainly happy they have made it so much faster for us ..im still learning. But this is great i got a sharpy and mark it on all my tins. ..

Awsome...thank you!!!

Thanks for sharing your hard work. 

Crusher

Great info, Thanks for sharing, the pellet my rifle like was listed and l liked what l seen on the Crosman Premier Ultra Magnum 10.5g.

Thank you HAM!

Certainly a lot of effort went into compiling the database but what practical or even theoretical significance does it provide? HAM's own write-up preceding the coefficients states "But note that Ballistic Coefficients are NOT, in themselves, a measure of accuracy."

Many Thanks. 

"beeser"Certainly a lot of effort went into compiling the database but what practical or even theoretical significance does it provide? HAM's own write-up preceding the coefficients states "But note that Ballistic Coefficients are NOT, in themselves, a measure of accuracy."

Click to expand...

This is because:
1) Accuracy is not linked to the ballistic profile of a projectile, although they correlate in some amount. Throwing a feather accurately is very hard.
BC value basically means, how close the projectile is to a cylindrical shape.

2) BC is not a pin-point value. Using it is like reading a train timetable. From one you can make good expectations, just like with BC you can make good expectations on where the bullet will land.

3) The idea with BC is that everyone should make their own BC charts. But that demands devices and time, and some reading first. So they published them to save YOUR time!

BC value basically means, how close the projectile is to a cylindrical shape.

How so?

This is because sectional density is accountable for most of the BC value.

This applies in GA and G1.

And not counting wadcutters, all bullets have roundish nose. So the rest of the bullet after the nose can be calculated by how much there is lead vs empty pockets of space.

And as most pellets of a single caliber are roughly the same lenght, how much lead per length is a good ratio.

This is why bullets with more length have better BC, sectional density rises.

This was a really great find. appreciate it!

Extremely convenient! Thanks for the effort put in this.

Really nice but no data on .25 AIrArms / FX Diabolo pellets vs JSB Equivalents 

Thanks for the link and to HAM for testing / providing this data.

I do have a question though: the testing was performed with an FX Impact-I'm assuming that is the 'FX smooth-twist' barrel that was on the gun (it wasn't listed)? If so, how do I 'convert' these BC's to the LW, LW-Polygon barrels I'm using on my gun? I'm sure nobody has the exact data, but my particular interest lies the .25 cal JSB Exact 25.4 grn and Exact heavy (and MkII) 33.95 grain pellets (through a Polygon barrel @ 900 fps from a RAW HM1000x) and a .30 cal JSB Exacts (44.75 grain & 50.15 grain) from the same gun. I'm also curious if there is data from the H&N Barracuda (31.02 grain, in .25 cal) pellets.

If anyone knows where I can obtain some of this data for these pellets from these barrels (and even from a RAW HM1000x would be an 'bonus, bonus'), I would appreciate it greatly.