Originally Posted by bigngreen
What BC's have you been using with the Matrix bullets, I've used .650 with the 165's and it seems close but haven't gotten them nailed down yet.
You should use the bullet SD and look at a similar bullet which would be an hypotical 7mm 175 VLD or Matrix's 7mm 190gr VLD.
I'm Canadian so for me Matrix has to be as good as Berger, therefore 165gr VLD BC is .326 G7 (or .636 G1) ;)
- Looking at Berger 7mm (0.277") target bullets: 168 VLD is .316 G7 and 180 VLD is .337 G7 so the 0.277" 165 VLD can be estimated at .326 G7 (or .636 G1).
- Another way to get an estimation is to use the same form factor as Matrix's 7mm 190 VLD (0.978) and divide the bullet SD (.307) by this number G7 BC = .307 / 0.978 = 0.313 G7 (or .613 G1).
One important note, VLD as G7 shaped bullets while standard spitzer are G1 or G8 shaped bullets. You'll get much better calculations if you use G7 bullet model and G7 coefficient to calculate external ballistics.
In any case, run out and get a copy of Brian Litz's (Berger Bullet's ballistician "Applied Ballistics for Long Range Shooting 2n Edition"