' lab, BCs DO change with velocity. Some Sierra manuals list 3 different BCs for each bullet as determined by velocity. Their 150 Spitzer Boat Tail is listed at:
.449 @ 2800fps and above. .416 @ 1801 - 2799fps. and .383 @ 1800fps and below.

Most " deer caliber" spitzer shaped bullets dont change the BCs from 2800fps and above. For those same calibers with round nose bullets, the BCs dont change from 2500fps and above. For ALL deer hunters, the difference in BCs as varies by velocities doesnt really matter and wont have an effect on most hunting type shots. Such info is typically only of concern for " technophobes" and target shooters of which typically only those firing in the 600yds and longer classes need be concerned. BCs dont matter at the muzzle, but when fired into varying conditions at a 10" circle at 1000yds you can bet the guys wanting to put ALL 10 shots in a Skoal can at that range, DO know about such effects!

Whack em where they stand!
RA