POP earlier you asked about bc of 168 TTSX being .470. Is there a formula you can use to find BC. I have a CPU program called point blank and it says it will calculate BC using muzzle and 100yrd velocities. does this sound right? IF so I'll give you guys the data next week(weather permitting). My '06 shoots them @ 2821fps w 16.6 stand,dev. will chron @ 100
bc formula for 168 TTSX
- Thread starter barthowes
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RiverRider
Handloader
- Dec 9, 2008
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BCs given by bullet manufacturers are theoretical for the most part, and are based on sectional density, form factors, and other stuff that's not too exciting (at least to me). A ballistic coefficient that is actually calculated using real velocity data is a bit more interesting (at least to me) because it takes into account bullet stability in flight. You might fire a bullet that has an advertised BC of .470 and find that velocity readings and calculations yield a real BC of .390, for instance. This would tell you that the bullet was not as stable as we would like and was shedding velocity due to the instability. The same bullet fired at the same velocity from another rifle with a different rate of twist might achieve a higher BC...or maybe not!
Oldtrader3
Ammo Smith
- Nov 6, 2009
- 8,406
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The other thing about ballistic coefficient is that it normally diminishes as velocity decreases. Down close to the speed of sound BC will be dramatically lower on many bullets.
