I have a like new model 37 Ithaca with a modified choke. I LOVE the gun. the only problem is i wish i could use screw out chokes as i would like IC or Skeet for grouse hunting and full for really late season pheasants. I know i can convert it to screw in chokes. I would love to know your thoughts on brands of screw in chokes and if they pattern as well as fixed chokes. Thanks for the help!