First of all, there is no such thing as a "flier." It's a term invented by gun writers to excuse poor accuracy in guns they test and get paid for testing. A gun either groups well or it doesn't.
If you calculate how much bullet drop a difference in velocity will make at 100 yards, you will find that even with moderate variations in velocity, the difference in bullet drop is very little. That means for 100 yard shooting, other factors are quite a bit more important in obtaining good accuracy than extreme spread. When ranges are increased, extreme spread becomes more and more important.