Sumtoy is right, it depends on your shell ( type and pellet size). My observations are based on a 11-87, basically the same as a 1100. My .660 works better (uniform tight patters with few "holes" in the pattern) with smaller pellets like #6. If I am shooting larger pellet loads like #5, I get better patterns out of my .665. Both of these chokes are Jellyhead.