I will research several printed/published load manuals to find what powder/bullet/case I will be loading and from that I have a minimum and maximum powder charge and what those charges will produce as velocity.
I always load with a chronograph. It tells me when something is not tracking with what I expect base on the data research. During the workup I am little to not at all concerned about variance and SD and do not in fact usually even tell the Chrony to do the calc. If I get the kind of accuracy I am looking for and haven't hit a book listed max I am done, at least with most rifles. With a rifle I am specific about velocity goals for I will keep pushing it up and looking for classic pressure signs while I am looking for a good node further up. Sometimes you get that node at or closely above a book listed max. Sometimes you don't. If I don't I move on to the next candidate powder and repeat.
Once I have a good load I will then start to wring it out. Look for a "window" to center the charge in, look for average and SD velocity as well as how wide ES is. After that I may test it against temperature. All the while running each shot across the chronograph.watching for irregularity. By the time I get done I have a very good idea of how close to Max I am with that particular rifle and load.
IMO there is nothing a chrony will tell you about max without that kind of testing, at least nothing I would care to hang my hat on.
