do your rotors have an arc/radius adjustment screw in front? When you adjust it for shorter arc, the screw often causes more water to sprayed at shorter distances. The downside is you might not get complete overlap on the long end but you might not get that now anyways.

If I adjust them back far enough, then the rest didn't get watered. With these I can seem to only water different areas or local, not both

Get this sprinkler. It has great coverage, is easily adjustable, and would be perfect for you because your lawn is square.

I have been considering an external sprinkler in the hottest months, but I would like to stick to the automatic system if I can.

Oops. Didn't realize you had an irrigation system. Scratch the above comment.

Check the plants around the lawn to make sure they aren't blocking the water with an overhanging twig. It doesn't take much, especially with water-greedy grasses like bluegrass.

Trying to grow anything but Bermuda or Buffalo grass in your area is very difficult, and water-intensive. Look into reseeding (now would be great - with one of the buffalo/blue grama mixes)

they would love the heat and after establishing would require far less water.

My Phoenix and Socorro buffalo grass experience

A more appropriate grass type like the bermuda that is "sneaking in" would help. Many people in the transition zone are using KBG in the cooler months & letting the bermuda take over in the hotter months

I've had similar problems with my Rainbird 5000 rotors. Switching away from the low angle nozzles helped. I went with the 5000 MPR nozzles, which were very hard to find in Canada. http://www.rainbird.ca/landscape/products/rotors/mprNozzles.htm

I would also recommend checking your valve(s) to make sure the water output control is all the way open. If your heads aren't getting enough water, they will not distribute properly.

I'm not a fan of using the adjustment screw on the sprinkler head itself, in most cases you should be able to find a nozzle that fits your scenario. If you're not able to find the right nozzle, you can try a nozzle that has a greater range than needed and you can use the adjustment screw to shorten the distance.

Just make sure you read the data sheets on each nozzle. Using the adjustment screw on the rotors doesn't decrease the water output at the head, it only decreases the distance. You should still calculate the output at each head based on the rotor nozzle and water pressure at the source. You want to make sure you have uniform distribution.

Off topic, but my grass is: http://gardnerturf.com/reveille/reveillefaq/

I was pretty frustrated at first about the Bermuda, but realized that resistance was futile, and that it was actually much more durable and didn't look bad. I stopped fighting it.

I looked at the 5000 series heads...maybe switching to the larger nozzle/heads would be worth it (current ones are very small).

You might get more comments in the Irrigation forum. I've always had a problem with single point sprayers and the Rainbird type of sprinkler, because they shoot water out away and leave the center of the circle relatively dry. They can be adjusted, but they're too fiddly for me to figure out. The oscillator is the only sprinkler that gets close to uniform coverage.

Several people have hinted that you would be better off with a different grass. What you have is a cool season, northern type grass, but you are located in a warm season location. You can make it work as long as you have unlimited water available, say, from your own well. You might be happier with a mix of prairie type grasses. Here is a picture of a lawn in Salt Lake City.