re: 9mm barrel differences and velocities

I think there is something missing in "the numbers" when using f/s.

Kinda like saying there's not much difference in water flow between a 3" and 4" drain pipe (only 25% difference in size). Yet in reality, the flow is DOUBLED!

I think we can agree that a 357 mag's performance dwarfs a 9mm, yet not much difference in velocity.

My Hi-Point 9mm carbine will punch a hole right through a 6" diameter pine tree at 70 yards, whereas a 9mm pistol fails to do so at 7 yards.

As is the case with pi in the diameter of a pipe (squared), perhaps something is something similar with f/s and flying bullets that we're not factoring? Need someone smarter than me for this.