Re: kestrel in G1 or G7 (as if I know what that means)
Of course advertised BCs are inflated, (it's how they sell a bullet) they are usually based on a higher MV, again, going with 175SMK example, the .505 advertised number is based off 3000fps. We don't shoot them at 3000fps. The .496 has been well used for years, and that handles most rifles with a MV over 2650fps very well, if your MV is less then that, a lower average probably works.
BCs are fluid because they are based off your rifle and MV, what I say for me, may not be the same for you because our rifles are different. The end result will vary, we use these "averages" as a starting point and not a finishing one.
Examples of banding both G1 or G7 can be found in a number of places, and this helps "adjust the curve" on the fly giving the software a better picture of the bullet's flight to use.
Go to JBM Software online for free, select the 175SMK with G1 and you can see an example of banding.
From a MV of 2800 to 5000 it shows .505
From a MV of 1800 to 2800 it shows .496
From a MV of 0 to 1800 it shows .485
This is an example of banding your BC, this is how the computer is figuring your solution. You can actually do it with anything and it works out well. And the computer does this automatically with G1 for you, no extra steps.
If you are "tweaking" your MV, either you are not chronographing or your BC is wrong, sure the chronograph can be off... but then again, if you are tweaking with any G Factor you are doing the exact same amount of work and can probably get the exact same answer out of G1 or G7. What is the difference in that case ?
Like I said, G1 has been around for a long time, and continues to be around. Bryan has done very well to match G7 to modern software, which in turn gives people excellent results with them. But the amount of effort can be the same, in the case of G7, you just let Bryan do most of it for you and hope it matches "your Rifle" better than you trying to do it.
But honestly, whether you use .475 vs my .496, or if you use .243 G7 vs me using .239, what is the difference... well us. How my rifle shoots vs your rifle that is the difference. Otherwise it's just a fluid number designed to get you on the right path to success. Someone people tweak the BC, others tweak the MV, we are doing the same thing, bending the curve.
Better program handles the information in better ways, follow that link you can read all about it. Ballistics AE does one thing, Bulletflight does another with the same information so using both together will yield two different results.
MV matters... and advertised BCs are not the end, but the beginning of the process.