From patterning board experience in setting up a dedicated grouse gun I found this out. At 15 yds or less it doesn't matter much, any choke is too tight. from 20 to 30 yards you will see a big difference in the spread of the patterns . Spreaders won't show a dramatic difference below 15 yds in a skeet/cylinder choke. IC/Mod works well with spreader loads in the open barrel to 25yds. I ended up at cyl/M and shoot 7/8 Oz 7.5's, 20 Ga. no spreaders, No complaints. As Karl pointed out after the leaves are gone you are going to be able to take some longer shots. Later season birds rarely hold and will flush "out there" too. I love my pointer dogs but have seen a very few that could work a spooky grouse and point them after the young'ns are gone.
Chief
