What will really improve your scores are a well fitted gun, good form and technique, possibly some instruction and lots of practice.
If you've done all those, the aftermarket chokes might help if your factory chokes aren't giving you the size and density of pattern that you want. A trip to the patterning board to determine what your chokes are doing is required.
I use Briley aftermarket chokes in two guns (Beretta and Browning). I find the chokes are more consistently manfactured than factory chokes. If the choke says Improved Cylinder than I can be quite sure that its .010" of constriction. Do they help me shoot better? I don't actually know but they look very cool with the knurled edges sticking out and are easier to change.
