I have to agree with Peezakilla. The reason the Stoney Point tool is so popular with so many reloaders is that very reason. (not to mention why Hornady bought the design) It makes simple what used to be less simple and even iffy.
Magazine fed rifles can be gauged as described, but often the limiting factor is the length of the magazine....it is usually shorter than the "just short of the lands" goal of a single-round-fed bench rest rifle. That said, I use the Stoney Point tool first, then adjust for the magazine if I have to.