hello dan13,
My god, you gave him a really good idea. (thanks for that because i am gonna copy that too)
I am making a similar turret but i was considering a dc motor and 8 switches to index the turret and that means a lot of wires and input/outputs to mach3. Now i will also use a stepper motor for the indexing and locking of the turret. (you are very right that using the incremental mode for the stepper will not care for the missed steps that are surely going to be there when the ratchet and pawl will meet.
maybe i will need some help from you on the macro's part later.
thanks,
jasminder singh