There are several factors to consider. The Maximum length is determined by bullet shape, magazine length and chamber.
I keep a logbook page for each gun, and one of the first things I do is make a note of the max length the mag will take with a round nose and a semiwadcutter bullet. (The semi has to be seated a bit deeper.)
Then take a loaded round of max length (no primer or powder), chamber it and drop the slide. Pull it out and see if there is a ring around the bullet just above the case mouth. If there is, the round was too long. Seat another one 10 thou deeper (about a quarter turn on the seater stem) and try again. Keep dong ths until the chamber does not mark the bullet.
3 of my 45's require a 230RN to be seated no longer than 1.230"
Note that the max OAL for a given bullet will be different from gun to gun and will differ for one gun from one bullet shape to the next.
Once you know the max, you can make up a test of max, and then two increments of 10 thou less and see if funtion and accuracy improve/get worse.