You dont need a rangefinder, but can use them to confirm ranges which are given. Some stages are ukd, so no rangefinders.
i think factory class will die out, its not really necessary. There were 40 competitors at round 4 and only one factory class rifle, and he won factory class, even with 6lb of lead weights added to his factory howa to completely change its charachteristics.
My 20+ year old r93 which cost £1200 when new was not allowed in factory class because new r8’s cost £3000 even though they have larger and detachable mags - figure that😂. I still beat a lot of customs and ai’s etc. And was hitting the farthest targets on elr day with a 15x scope.
its not the rifle that wins, its the shooter.
enjoy!