Mr. Reb8600:
Re-read my post; I didn't say "every load" in the manuals will shoot good...I said it allows you to "seldom guess" i.e. it reduces most of the 'guess work' to experimentable parameters (along with the reloader making a comparison to the other loads in the manual).
It's the scientific method replicated by the manuals so the individual is not literally starting from scratch! And, I used the word "test" ...
I did not say 4" at 50 yards (you did).
Almost every factory hunting bullet from Sierra, Hornady, Speer and Nosler will shoot significantly better than 2 inches in the majority of factory rifles today [closer to 1moa/1 inch] once powder and seating variations are refined.