You can get manuals at the Smith and Wesson website.
first but a bullet in it pull back the hammer and shoot it into your knee
You can request a owner's manual for free at the S&W web site.
A shotgun made for Smith and Wesson, sold under the Smith and Wesson name.
Go to S&W's web site and request a manual. I have not seen one online. If they don't have one for you, find a copy of Gun Digest's "How to....." series. They did a book on revolvers, pistols, shotguns, etc..
If you go to You-Tube and type in disassemble of Smith and Wesson model 915;there should be a video of the steps needed to take down your smith and Wesson semi-auto 9mm.
Ask a gunsmith.
If you actually have a Smith & Wesson model 916 shotgun marked "Eastfield", instructions may still be available from S&W. The shotgun was not a success in the market and was withdrawn after a couple of years.
Contact S&W on their web site and request a manual.
You need the services of a gunsmith.
If you contact Smith and Wesson directly,they should be able to provide the information that you seek.
Ask a gunsmith for help.