I own a Mossberg 835 Ulti Mag 12 gauge shotgun 28 inch barrel, all camo gun , and I think it is an excellent shotgun to have with excellent patterns. Mine came with 4 different chokes that allows you to hunt a variety of game and if you want, sheet or trap shooting. In addition I have purchased a super full comp n choke for turkey hunting.
The other guys are correct, extra full (very tight patterns) on down to imp cyl. (spreads fast) are what the chokes do. And speaking of the Mossberg, it has a back bored barrel, bored 10 gauge, chambered for 12 gauge, which makes the shot give you excellent patterns.
So if you are looking for a good shotgun that is dependable, that also can stand up to rugged use, such as duck and geese hunting, the Mossberg 835 Ulti Mag is an excellent choice. This is only my opinion.
Swampchopper