Most discussions that open up with the question "what barrel length should I get" yield a variety of answers. Most are "depends on what you want to do with it" or "I have a barrel that's xx" long and it does all I want it to".
,
This morning I got to thinking that there has to be some data out there that supports an "Optimum Barrel Length" theory. I've seen references to X number of "calibers" in barrel length where the diameter of the bullet is divided into the barrel length, or bullet is multiplied by a proven factor to determine barrel length.

Is there such a magic number? If so, what is it for the common calibers used today in LR and/or Precision shooting (.223, .243, 6.5 Creed/.260/6.5X47L, .308, etc).

I know that everyone who's built a rifle has relied on recommendations of friends, forum members, gunsmiths, articles, etc to select their barrel length but I was just wondering if their was a scientific formula?


What say you all?