I've seen numerous posts here about the B.C. being calculated/verified by shooting. How is this done? I'm assuming it has something to do with m.v./downrange bullet impact relative to line of sight. Right??
It's actual fire at known ranges to get the clicks or MOA needed to put the bullet that is being used as the test bullet, on target.
We check the computer drop charts as to what it calls for, using "THAT" bullet to see where this actual fire falls in place.
If a certain manufacurer says a bullet has a BC of whatever, and you run the ballistics and find that it will need say 20 MOA to get to 1000 yards and the bullet gets there from a 100 yard zero with "less" MOA, then the BC is probably better then listed.
The reverse is true also if it takes more MOA to get to the same range.