Whatever you do don't waste your money on a 3 1/2 inch semi automatic gun. I had a Winchester SuperX2 and a Remington 870 magnum and they both had problems.

Mossberg just came out with there new and improved 9200 auto 12ga shotgun. I don't know if they changed the model number on it, but what they improved on was they made it into a 3 1/2 inch gun. If you can find one of the other 9200 3inch guns, that would be the gun that I would buy. It's one very sweet semi automatic shotgun!

Remington makes some fine automatic guns also. I own a Remington 1100 2 3/4in gun with the 30inch full choke steel shot only barrel. It don't all we's like to eject the 3inch shells. I did have for some time a Remington 11-87 SP 3inch auto 12ga shotgun. Talk about one sweet shotgun if all you are doing is shooting magnum loads. They also have a Remington 11-87 all propose shotgun. It will take all 2 3/4-3inch loads. After I sold my first 11-87 I was thinking of buying the all propose one but had other stuff on my list of things to get.

Weatherby makes an autoloader 12ga for a fair price. The Weatherby SAS. I know someone that has one of them and they have yet to have a problem with it.
Stoeger, Tristar, and Charles Daly both make good all around 3 inch auto guns for a well price.

If you are looking for a good pump gun. The Winchester 1300, Remington 870, and the Mossberg 500/835 are some of the best built shotguns on the market and all 3 anyone can pay for.

Let us know what you end up getting