Berger sont de très bons boulets. Par-contre plus dispendieux que les sierra.Ils vont sortir leur manuel bientôt en attendant envoie leurs tes détails à cette adresse et tu aura des data.
bergerltd@aol.comPour la différence entre le G1 et G7 c'est plus compliqué un peu, c'est une question de configuration d'ogive. Tous ce que je peux te dire c'est que le G1 c'est le plus populaire et que le G7 c'est pour les VLD
Si tu comprend l'englais, ca va t'aider un peu.
Differing mathematical models and bullet ballistic coefficients
Most ballistic mathematical models and hence tables or software takes for granted that one specific drag function correctly describes the drag and hence the flight characteristics of a bullet related to its ballistics coefficient. Those models do not differentiate between wadcutter, flat-based, spitzer, boat-tail, very-low-drag, etc. bullet types or shapes. They assume one invariable drag function as indicated by the published BC. Several different drag curve models optimized for several standard projectile shapes are however available.
The resulting drag curve models for several standard projectile shapes or types are referred to as the:
G1 or Ingalls (by far the most popular)
G2 (Aberdeen J projectile)
G5 (short 7.5° boat-tail, 6.19 calibers long tangent ogive)
G6 (flatbase, 6 calibers long secant ogive)
G7 (long 7.5° boat-tail, 10 calibers tangent ogive, preferred by some manufacturers for very-low-drag bullets[10])
G8 (flatbase, 10 calibers long secant ogive)
GL (blunt lead nose)
Since these standard projectile shapes differ significantly the Gx BC will also differ significantly from the Gy BC for an identical bullet. To illustrate this a bullet manufacturer has published a G1 BC of 0.659 and a G7 BC of 0.337 for their 7 mm Match Target VLD bullet and has since published the G1 and G7 BCs for most of their target bullets.[11] In general the G1 model yields compariatively high BC values and is often used by the sporting ammunition industry.