DocUSMCRetired
Well-Known Member
Are you programmed to incorrectly picture what a BC should look like?
What do you think of when you think of a BC? Does a simple one number solution come to mind? Or do you picture a velocity band? When you talk about the BC of a bullet, it is important to make sure that you don't forget the other half of that number. A BC should always be followed by an indicator. It is not just enough to call upon a single number. By using a single number you don't see the entire performance of the bullet. You also don't get a fair comparison of one product to another. Making it easy to push a little marketing hype in to what the consumer thinks. This can also hide a bullets true performance, and some bullets have a wide variation in BC from Mach 2.5+ to Mach 0.9-(Subsonic), while others are more consistent. Anytime you see a BC you should be asking yourself "at what velocity". All BCs published by Applied Ballistics are averaged from 3000 fps to 1500 fps. Averaged is the key word here. It is important that the consumer understands comparing apples to apples. You cannot take a Mach 2.5 or high BC and compare it an averaged BC or a Mach 2.0 or Mach 0.9 BC etc.
A BC is only true at 1 specific velocity, which is why you can find velocity bands published in the Ballistic Performance Book, but also why you can twist a little marketing hype in to them by using the highest performing velocity band as the published BC on the box. (You can hide a bullets flaws this way) As Bryan put it "The BC changes a lot over the flight of the bullet."
As a shooter anytime you see a BC you should be seeing 2 indicators. Think of it like when you look at a cars mpg. The cars list "## highway, ## city". Well a BC should say "## G7 Averaged" or "## @ Mach 2.5 & ## @ Mach 1.0 & etc. ". You could use ## G7 @ 2800 fps, and it would be just fine. As long as you know where in the velocity band that BC was calculated at, it allows for a more honest comparison against other bullets. So the next time you see a BC the first question that pops in to your head should be "where is the rest of the story" followed by asking the question "at what velocity".
Of course, if you use Applied Ballistics CDMs you don't have to worry about velocity effects of BC as your bullets drag is being modeled all together. Giving you not only a more accurate prediction, but also removing any marketing bias. However we know it can be hard to compare bullets on the shelf this way. So it is still important every time you see "BC G# 0.###" that you ask yourself "At what velocity".
What do you think of when you think of a BC? Does a simple one number solution come to mind? Or do you picture a velocity band? When you talk about the BC of a bullet, it is important to make sure that you don't forget the other half of that number. A BC should always be followed by an indicator. It is not just enough to call upon a single number. By using a single number you don't see the entire performance of the bullet. You also don't get a fair comparison of one product to another. Making it easy to push a little marketing hype in to what the consumer thinks. This can also hide a bullets true performance, and some bullets have a wide variation in BC from Mach 2.5+ to Mach 0.9-(Subsonic), while others are more consistent. Anytime you see a BC you should be asking yourself "at what velocity". All BCs published by Applied Ballistics are averaged from 3000 fps to 1500 fps. Averaged is the key word here. It is important that the consumer understands comparing apples to apples. You cannot take a Mach 2.5 or high BC and compare it an averaged BC or a Mach 2.0 or Mach 0.9 BC etc.
A BC is only true at 1 specific velocity, which is why you can find velocity bands published in the Ballistic Performance Book, but also why you can twist a little marketing hype in to them by using the highest performing velocity band as the published BC on the box. (You can hide a bullets flaws this way) As Bryan put it "The BC changes a lot over the flight of the bullet."
As a shooter anytime you see a BC you should be seeing 2 indicators. Think of it like when you look at a cars mpg. The cars list "## highway, ## city". Well a BC should say "## G7 Averaged" or "## @ Mach 2.5 & ## @ Mach 1.0 & etc. ". You could use ## G7 @ 2800 fps, and it would be just fine. As long as you know where in the velocity band that BC was calculated at, it allows for a more honest comparison against other bullets. So the next time you see a BC the first question that pops in to your head should be "where is the rest of the story" followed by asking the question "at what velocity".
Of course, if you use Applied Ballistics CDMs you don't have to worry about velocity effects of BC as your bullets drag is being modeled all together. Giving you not only a more accurate prediction, but also removing any marketing bias. However we know it can be hard to compare bullets on the shelf this way. So it is still important every time you see "BC G# 0.###" that you ask yourself "At what velocity".
