I can't really say much about shooting quail, as I've never had the oppurtunity to do so. But for shooting pheasants, #6's through a modified choke at 30 yds. will work well. Later in the season when, most birds are more mature and perhaps somewhat spookier, I would think about using the 5's. 2 3/4" would be fine. Just be sure you get the 1 1/4 oz., 3 3/4 dram equivalent loads. Good luck to you.

early birds that flush close.no.6 shot high brass.
hunted birds that flush out at 30 yds etc. no 5 shot high brass.
i like IC choke also

I was using 6's today, we also used 8's but if your a good ways away that only wings em, 6 shot gets really good shots off at any distance, to close and it can really tear the bird up though. So its really personal preference and how far you think you'll be when the bird pops up.

Pheasants at 40 yards are a little far for me. They are knocked down, but unfindable, even with a dog at times. Give me 25 to 30 yards with 7 1/2 down to 5's.