I sure do enjoy your posts and answers- they can brighten up a man's day like a home-made pie from Aunt Bea herself--and I'm glad you caught my drift on the "nose' business--we need to remember that when we invent excuses for missing an easy shot- usually it is a mechanical problem- a loose nut behind the stock group- so to speak--
And I wonder, wonder-wonder- let me guess here- the rest is "Who wrote the book of love" maybe? No big deal, I just love trivia and history quizzes is all.
The difference between No 5 shot and No 6 (lead shot) is one thousands of an inch bigger for the No. 5- old easy formulae (and not Pi R squared)-- take 17 and subtract the number of the shot size- if you are shooting No. 2 shot- your pellets are (in theory) 15 thousands of an inch in dia. We all know that shot when it leaves the muzzle and the shot cup falls away, not all fly true, not all stay round- ballistics for smoothbore weapons, is NOT an exact science- but folks like Tom Roster and others have sure worked hard to make it close to that--
As I mentioned the old Pi R Squ. theorm- here's a Jeff Foxworthy spin on that puppy--I kinda liked it-- Little Tommy comes home from grade school and at the dinner table, his Pappy asks him: "Well, Son, what did they learn you today in school?" "Math-e-matics, Pa" was the lad's reply--- Huum, says the father-"Math-E-matics, what sorta learnin' is that?" "Well, Pa, we learned that Pi R Square today!"-- "Horsefeathers, said the father, any danged fool knows that Pie are Round, it's johnny cake and cornbread are Square!"" Bon Appetit!!