ORIGINAL: stalkingbear
I would use the larger #4 shot for these facts:-they are larger,thus having more individual pellet energy,the pellets that do hit will penetrate deeper,true-there are less pellets than with #6,what that transalates to is less pellets in meat/less bloodshot meat,and having more individual pellet energy-will extend range of clean kill assuming you stay within your effective pattern range.
I too was thinking of a full choke and using #4 - but some argue that #4 will push hair into meat.
I am fairly sure I am going with full choke, but still not sure on shot sizes.