So you think YOU'VE got a big sprinkler in your yard? Here's my Nelson SR100 24º Big Gun sprinkler on a 7ft tall by 2" riser watering the back-half of the backyard. This gun puts out (on average) about 160 gallons of water per minute at around 55psi, covering a radius of around 150-160 feet. It's being run by a Pacer pump with a 5hp Briggs & Stratton gasoline engine, which has a max output of 195GPM. I can water the yard in about 10 minutes whereas it would take around 45 minutes to an hour to put out the same amount of water with an underground sprinkler system!