I'll weigh in, not as an expert, but with my experience and frustration with a new auto. With my old pump, I shot well. With the new auto I couldn't hit s...! When I went back to Bryan at Fieldsport where I bought the Beretta he had me bring in my old pump took measurements, looked at my gun and eye alignment when mounted. made shim adjustments, put on shorter stock and I killed the next 12 ducks I pulled the trigger on. I went back a believer in gun fit! I then did a true fitting, plate work, (where you shoot at a steel plate at 10 yards to see where you actually hit when shouldered and shoot), and finally a shooting lesson with a trained shooting instructor. Bryan made a believer out of me. Oh ya, and put away those progressive lenses...they effect you seeing the target clearly. I next took in my daughter, who was completely frustrated shooting at pheasants and ducks. Her fit and mount were never going to work. Many of us buy a gun out of a box and expect great results. Spend the time and money to get a fitting! We spend so much on boats, decoys, trips and gear, but don't do the most important things to ensure a rewarding hunt. My daughter also was gifted to do Fieldsports shooting school with Bryan and Michael McIntosh. And to think I almost did her a shooting disservice by not starting with a proper fit. She just rewarded me with asking if she came home from Virginia for a week on the 31st, if we could go to duck camp for 4 days and hunt pheasants for a day. Maybe she just wants to help me with my new hip, but I know it's probably things like that special time before sunrise, when ducks are talking, or the birds in flight that respond to the call and set their wings over decoys we painted, or marsh scenery that most people wouldn't call beautiful.
Thanks for reading my rant. I just came back from a great hunt with Rick Ligman and I can thank some of that enjoyment to a proper fitting.
One more thing...how many of us practice frequently a proper gun mount. That should be something we practice to ensure a proper cheek/shoulder mount. If that doesn't happen usually everything else after that will lead to a missed target. People who are good at what they do well, practice.!
We're into the migration my friends, be safe and enjoy your hunt.
Louie.