Originally Posted by ArTurf
So the #4's covered the 40' without dry spots?
Square spaced rotors with the right size nozzles and verified adequate volume/pressure can do that. On the rare occasions that I am installing from scratch, that is how I space heads with a 10% derate for wind. I often run into systems where rotors are spaced like impacts assuming 100% coverage from head to end. So they are placed diagonal of each other, two heads in a square or rectangle.
Good way to kill a lawn in an area that only gets 20" of rain per year in a 365 day growing season.