Alright so as some of you may know im young and still learning about guns, i own a few rifles and a two .22 pistols but the only shotgun i have ever owned was a 20GA single shot break action.
Heres the deal, my grandfather gave me a Smith and Wesson model 916A 12GA shotgun like the one pictured, it has a 28 inch barrel and what i believe to be a 5 round tube magazine. Its my first pump though i have shot many pumps before this is the first one i have ever owned.
Now the problem, when he gave the shotgun to me it was broken and is still broken, from my basic knowledge i can tell you that its missing a magazine tube spring and follower, the other problem is the one im coming to you for, when i pump it the bolt does not move, the rail on the pump just doesn't catch anything and slides back and forth freely without moving the bolt or anything. I know the bolt moves cause i can cock it by prying it open and i can push it closed with my thumb, i have put a 12GA round in it with just a primer and no powder and fired it and it did fire fine so i know the bold and everything is in order so its the part that the rod on the pump catches on the bolt that must be broken.
I figured out how to take the bolt out of the shotgun by removing the stock and a screw that holds the trigger assembly in and just sliding the whole trigger group down so the bolt falls out the back. According to the schematic the bolt is just fine and missing no parts so its something inside the gun thats messed up.
I will post the schematic to help you figure out whats wrong with it, i thank you for any help in fixing this thing cause when i get it fixed im gonna have a gunsmith shorten the barrel to about 20 inches and use it for my home defence gun.
Before anyone asks i was going to take it to a local gunsmith to have it looked at so i could repair it but the guy wanted $50 just to look at it and $100 to fix it plus parts cost, i just hung up the phone after that cause hell i could buy another one of those for that cost.

jonlisha!!DjAwRmA2H1 10/03/09(Tue)18:13 No. 2888 ID: 16270a File: st2888_1980z916-A.jpg-(57.33KB, 640x479, 1980z916-A.jpg) Oh and tl;dr My shotgun bolt won't move when i pump it, somethings not catching and i have no experience in shotgun repair so im asking about what part is broken and how to repair it. Heres the other pic, maybe it will help i took it from Numrich.

jonlisha!!DjAwRmA2H1 10/03/09(Tue)18:15 No. 2889 ID: 16270a File: st2889_dsc09272.jpg_thumbnail1.jpg-(20.52KB, 640x291, dsc09272.jpg_thumbnail1.jpg) If any more pictures of my shotgun are required i can take them, inside the gun or out. Pic some what related, i plan to have a gunsmith cut it down to that size if the 20 inch barrel cost to much.