A good friend was given a Stevens 820B 12 gauge shotgun from his father-in-law. He asked me to clean it for him. Neither the friend nor his father-in-law know much about shotguns. The father-in-law took it to a gunsmith every time the gun was cleaned. So, neither my friend nor his father-in-law know how to disassemble this 820B. I am familiar with disassembly and reassembly of Remington 870 Wingmaster pumps and Benelli semi-autos, but they are very different from this gun.

I cannot figure out the first step of the disassembly past confirming the gun is not loaded and engaging the safety. I have been unable to find either an Owners Manual on line or a Youtube video showing disassembly of a Stevens 820B.

I found two Stevens 820B Youtube videos concerning removal of the trigger assembly and removal of the fore end, but not removal of the barrel. The removal of the fore end video involves unscrewing the screw at the upper end of the magazine tube that is pointed out in one of the photos below. Hopefully, I will be able to use the other video for removing the trigger assembly and bolt for cleaning. But there is no such video I found of removing the barrel.

I found a Youtube video about disassembly of the Stevens 520/620 pump shotgun that showed turning the grooves on the upper end of the magazine tube until the end of the magazine tube started to separate from the frame. This 820B has groves in the same location as that shown on the 520/620 video, but after turning the magazine tube several rotations, I could not get it to turn further, and there was no separation of the tube from the frame. I am afraid to try to force it further because the video was not specific to the 820B and I might harm something unintentionally.

I was able to find, however, written instructions for disassembly of a Stevens 820B on another forum, but it says to first, "rotate the locking nut clockwise, which is located at the end of the magazine. Continue turning it until the alignment pin, which protrudes into the locking nut comes loose. Move the locking seat out of the way and swing the loose barrel to the left. . . ."

I do not know what to look for in either a “locking nut”, an “alignment pin. or a " locking seat” I am attaching pictures below of what I believe to be the applicable portion of the gun. However, I still do not know what to do for the first step.

Can anyone help me get over this hump? Can anyone tell me, or show me, how to remove the barrel for simple cleaning?