6,5 × 57 XRG 130 gr (Rifle ammunition with eXergy bullets)

Reading these numbers

Both a G1 and a G7 ballistic coefficient are published for this bullet. BallisticApp defaults to G7, because the G7 standard projectile is shaped like a modern boat-tail bullet and holds its coefficient far more steadily across the transonic range than G1 does.

Muzzle energy of 2709 J (1998 ft·lb) is computed from the bullet weight and muzzle velocity above, not quoted from the catalogue. Sectional density 0.265 describes weight per unit of frontal area; divided by the ballistic coefficient it gives the form factor, which is how much drag the shape adds over the standard projectile.

Among the 187 loads of this bore diameter in the database, this one's G7 BC of 0.121 is higher than 0 of them.

Similar 6.72 mm (.265") loads