I guess it depends on one's definition of good. I'm nearing the end of my stash of OW #6s. There's a farm store nearby that has 10-12 boxes of the #5s. I bought a box to pattern. While they pattern evenly, the density starts to wane quickly after 40yds.
It's kind of a waste in my mind. There's plenty of energy to kill a long, long way, but there's simply not enough pattern density beyond 45yds. Clearly, the #4s would be even worse. I'm sure you'd be good on pattern density to 40yd, but you can do the easily do the same with lead #5s and #6s.