Bullet BC for 45 cal.

[bruce moulds]

eric,
it is next to impossible to calculate b.c. using the various calculators available to us, as they do not take into account the drag due to various nose forms and grease grooves in theit various forms or lack thereof.
I suspect that the mlv figures were derived from shooting with 2 chronographs at closer ranges.
this puts the readings in the highest drag area of the transonic zone of most cartridges, which can lead to lower b.c. readings than for average flight., although correct for the ranges shot.
the best way to establish b.c. has proven to be shooting at 3 or more ranges to establish sight settings.
you will need to know your sight radius to convert to true moa, and the muzzle velocity.
with these figures, you can run jbm ballistics repeatedly trying different g1 b.c. numbers until a trajectory matches yours.
you will need the barometric conditions and elevation above sea level for accurate numbers.
doing this will give some interesting surprises, like how much grooves and rings reduce b.c., with the corresponding increase in wind deflection.
if possible, 3 good ranges are 300, 600, and 900 yards or meters.
this is because good long range bullets are transonic out to about 700 yards, and you will go past this.
keep safe,
bruce.