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First of all, this isn't a debate about if it's good or bad or useful or not... so, What is the relation between BC and rate of deceleration? I know that the relationship is the basis of determining BC, but has it been quantified? I'm thinking about calculations of first shot precision using air density, BC, and muzzle velocity. | ||
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BC is simply the bullet being considered vs a standard bullet (1" diameter solid, 2 ogive nose radius, etc which was assigned a BC of 1.000. The velocity loss of this bullet was determined by actual test firing). Bullets with a BC of 2.000 decelerate 1/2 as fast, those with a BC of 0.500 decelerate twice as fast, those with a BC of 0.250 decelerate 4 times as fast etc. | |||
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Quote: Inversely Proportional. The higher the BC, the slower the rate of deceleration. | |||
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I don't know what you are trying to use the BC for, but: I use the relationship caused by the reference projectile loseing 1/2 its energy at 1,000 yards when fired at rifle velocities, that would be around 3,000 fps. The drag goes to 1/2 or maybe 1/3 when under the speed of sound, so it won't be anywhere close when you get around 1,000 fps. This means that a 30-06 bullet with a BC of .270 with 2800 ft-lbs at the muzzle will drop to 1400 ft-lbs of energy at 270 yards. It also means the a 30-06 bullet with muzzle energy of 2800 and drops to 1400 ft-lbs at 450 yards must have a BC of .450. JerryO | |||
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