I wanted to take a quick moment and talk about the Shotgun Magazine Extension Tube. We add these to every SM-1 Package that leaves the door, and it is the shotgun accessory we get the most questions about. The Magazine Extension tube shown above is our preferred tube. It is from Wilson Combat who as you know, makes some great stuff. We chose this tube to be part of our shotgun packages several years ago because of its design and ruggedness compared to man of the tubes that are available today. It isn’t the cheapest tube, and we only make $3 every time we sell one, but we think it is worth it.
The Shotgun Magazine Extension is a necessity if you are in competition, and a very nice luxury for law enforcement and home defense purposes. One of the things though that can plague many tubes available is a feeding issue. While they don’t happen often, it does occur and when it does it is maddening.
Generally what happens if you have a feeding problem is that the spring is binding where your Extension screws onto the existing tube. The best tube is a one piece tube from the factory because it eliminates this problem entirely (btw: the tubes on the Remington Tactical 870’s are not one piece). The after-market tubes will all deal with this issue from time to time. I have seen it most often show up while trying to load the shotgun. I have experienced this several times while building the SM-1.
The remedy can be two fold: First, you can unload the shotgun and try again. Many times this will alleviate the loading problems. Second, you can load one or two rounds and run the gun. Now is the part where we get into my theory and this is always scary! My theory for most of these problems is the lip the spring has to travel over in the extension. However, when you put on an extension you are twisting it on, and therefore you are twisting the spring. I think it is possible that the spring itself binds from the twisting. I haven’t had an extension that wouldn’t respond to those two simple steps.