1. ## Co-efficiency

What is co-efficiency and how is it calculated? I've got the Strelok app and the Geco ammo I bought today doesn't list it. Any ideas?

Cheers

Jonny

2. might you mean coefficient rather than co-efficiency?
if so, then I guess that's the same thing as BC.
I use Shooter though, not Strelok

3. I'm sure the BC for whatever projectile you bought can be found on their website: GECO: GECO

Which projectile and calibre is it?

4. Yes coeffeicient! What's BC? I've been on the Geco website and couldn't see it. It didn't give much info compared to Sako for example. Its 10.7 grams express in 308.

5. Ah BC is ballistic coefficiency! Just seen BC value in the table. 0.404 fills in the blank. Does anyone know what it means though?

6. Originally Posted by Jonny Boy
Yes coeffeicient! What's BC? I've been on the Geco website and couldn't see it. It didn't give much info compared to Sako for example. Its 10.7 grams express in 308.
Look at the top of the tables (BC= Ballistic coefficient)
BC-Value: 0.404
GECO: Centerfire rifle cartridges

7. BC is a mathematical figure used to define the air resistance of a projectile. Higher numbers indicate a more streamlined projectile that passes through air more easily. There are different ways of calculating BC with the commonest but possibly less accurate one being G1 and the potentially more accurate at long range being produced using the G7 model. G1 and G7 BC values are not interchangeable so only use g1 in ballistic apps unless you are certain that you have a G7 value

8. Originally Posted by Jonny Boy
Ah BC is ballistic coefficiency! Just seen BC value in the table. 0.404 fills in the blank. Does anyone know what it means though?
The higher the number the slippier the bullet.
Nice article for the beginner:
http://www.chuckhawks.com/bc.htm

9. OK thanks srvet and greener jim. That helps a lot

Cheers

10. Welcome mate

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