I bought a used Blaser F-3, and it came with a set of Muller stainless chokes. I had settled on LM for chokes with my other sporting clays guns, but when shooting over the snow the patterns made by the U2 chokes looked smaller than normal. So today, for the start of our sporting clays league, I decided to try the U1 chokes. I shot my best score ever on our local field, and even the longer range targets were breaking nicely. The U1 chokes measure in between the SK and IC Briley chokes, but the patterns appear to be tighter than IC with my other guns. This just shows that a person needs to actually pattern a choke with the chosen load, and not just trust the choke label.