Yes I did see the recommendations of starting OAL in the book. The otehr book (one caliber, one round) as well as LEE's booklet has different OAL starting points as well. <-- not to you but more the book author's!
Why does Lyman say to start at 1.275 and also state that is the MAX as well? Seems rather dumb? Sort of like OK you can start end (1.275) and oh BTW the end point is 1.275. So in essnse don't move off the 1.275. Yet in doing measurements I know 1.271 works in my weapon and other books give 1.200 - 1.275 as a starting point.
Lyman's manual is playing it safe, but they DO tell you which make of bullet they used (Speer). You will find that the heaviest jacketed bullets will often be seated to the max OAL for a pistol round. They have to put all that bullet somewhere!
Just keep 2 simple things in mind while deliberating over all of this:
1) Follow the published load data from the bullet manufacturer, if it's available.
2) Safe load pressure is a function of charge weight, bullet weight and seating depth. Start low and work up until you have a functional, reasonably accurate load.
If you are going to load at or near max charge, seat the bullet out as far as you can and not be into the lands. If you don't understand the whys and wherefores...just follow what the book says and stay out of the danger zone.