Mr. Goo,
Welcome to ALR.
You might find a degree of skepticism about a "3 - 5 rule." There are some in the gun-making community who have co-opted the ancient Greek philosophy of the "golden mean" from ancient Athens and combined it with the ancient Greek fascination with the 3-4-5 right triangle to come up with a theory I have been accused of referring to as the "grouchy moon". According to the theory of the grouchy moon there is a "magical ratio" of 3.
?? to 5.
? that is a guaranteed formula for artistic bliss. I have never used the theory of the grouchy moon in the construction of anything, including rifles, which probably explains why my guns look so crappy.
The ancient Greeks, not having TV, radio, videogames and Facebook, pondered things numerical in their free time and were fascinated with the fact that the ONLY right triangle whose sides were integers is the 3-4-5 right triangle. All other right triangles, ones with a 90 degree angle at one apex, have at least one side that is a fractional length. Pythagoras, of Pythagorean Theorem fame, proved that the 3-4-5 right triangle is the one and only. The 3-4-5 right triangle became the basis for almost all ancient Greek architecture as these proportions were deemed to be "special", handed down from the gods. Concurrently, in Athens there was the popular notion that the ideal person was one who was totally average - not extreme in any physical dimension. This is why all those ancient Athenian Greek statues are of people with "perfect proportions - no double-D cups nor double-A cups, no skinnies nor chubbies. The average or "mean" was seen by Athenians as the ideal form as intended by the gods. Athenian philosophy used the term "golden mean" for this concept. Somehow these two disparate tidbits of ancient philosophy got mashed together in the concept of the grouchy moon. Don't ask me how - I don't know.
So now you know more about ancient Greece than you ever wanted. And the hornet's nest has been kicked. Take cover!
Best Regards,
John Cholin