I am duck hunting with my friend in two weeks and I need to buy a new choke for my shotgun. I have a rem. 12 ga. but its a turkey gun with 21" barrel and extra full choke.

I was wondering what choke I should go with. Improved or modified?

Large ducks over decoys shot size would be 3 to 2, you could use either improved, or modified.

Make sure it is for steel shot though.

Modified

Well depending on how far you plan to shoot. Modified - 35 yards.
Improved Cylinder - 30 yards. So I would go with Modified if anything.

yeah if i were only buying one choke i would go with the modified .... i like using an improved over dekes in small sloughs, ponds, timber, etc .... but later in the season or on bigger water ill go with the modified ..... good luck ... keep us posted how ya do

Do you think the shorter barrel will hinder the performance out to longer distances?

I have a 28" barrel. So I dont know. I think there is a certain length you need. I dunno know.

I owned one of the guns in question for quite a few years. I had best performance with an Improved Cylinder choke, the short barrel IMO really hinders tricky shots on ducks it just never swung well for me, 26" barrels + seem to work better for me, but all in all my vote goes to the IC

Go with modified. Here in MO there is a lot of marsh hunting and you might get shots on the outer edge. The short barrel won't affect ballistics or pattern, but will not swing as smoothly.