hi jeff -
don't get too worked up about what choke you are using. i don't. choke is a barrel constriction or taper that gives you a larger or smaller shot pattern. a cylinder bore, that is no choke, will give you the largest shot pattern. improved cylinder gives you a slightly smaller pattern letting you hit stuff that is farther away, modified and full chokes provide smaller patterns respectively.
most rookie wing hunters tend to over-choke. the tight chokes can help for those second long 'hail mary' shots when using SxS's, pumps, or autoloaders. my experience is that seldom do you bag a bird on the second or third shot based on choke. concern yourself with mounting the gun, getting on the bird, establish the proper lead, pulling the trigger and following through.
(if there was only one thing i could recommend to a freshman wingshooter, it would be to shot skeet low gun.)
if you're on, you have the right lead and the bird is within a reasonable range, it will fold up like an accordian, or book if you prefer. most newbies i hunt with show up with 3" 12 gauges sporting full chokes and a 1 3/8 ounce load of #4's. they usually blow up the first few birds to the point where the dogs have trouble finding the beaks and feet that may have hit the ground. bird-burger. i can say that i was guilty of all these things when i started out.
for birds from bobwhite to grouse, a 410 with 1/2 oz of #8's with work fine regardless of the choke as long as the bird is 10 - 20 yards away. if you do the "flush-bang !" and actually hit the bird, it does not matter what gauge, choke or shot size it, the bird will be toast. bird dioxide.
for pheasant, start out with 1 1/8oz of #6's in a 12 or 7/8 oz in a 20 gauge. as you get better at you can go to smaller shot size. less meat damage, etc.
i personally use a 410 with a full choke for all birds from bobwhite to pheasant. i hand load everything, bobwhites up to grouse get 1/2 oz of #8's while pheasants are treated to a special meal of 1/2 oz of #6 magnum shot.
so remember, for birds, don't worry about choke, barrel length, or your hair style. mount he gun fast, get on teh bird fast, use the proper lead, follow through, and learn dog control, these few items will fill your bag long before any effects of the choke you use will.
i am not a deer hunter, there are many guys here more qualified to talk about buck shot and slugs.
have fun !!!!
sg