Kalashnikov Concern has published some images and information about a very interesting pump action shotgun design. The shotgun is called MP-131K. It was designed in 1997 and sold in very limited quantities. What sets it apart from an ordinary pump-action shotgun is that it can feed both from traditional tube magazines and from detachable box magazines.
The tubular magazine can be loaded when the box magazine is detached. So the shooter needs to load the tube first, then attach the box magazine. In order to choose the feeding source, one needs to switch the selector lever on the right side of the box magazine body. The box magazine itself has a sort of a dual body construction. It is like a normal box magazine placed inside an outer shell. The actual inner magazine can move vertically inside that shell. So when the tube was selected as a feeding source, the selector lever lowered the inner box magazine, thus moving it away from the tubular magazine’s way. At that position, the tubular magazine was exposed and could feed the action. When the selector switch was turned up to its vertical position, it raised the inner box magazine, which blocked the tube and the action could be fed from the box magazine.
MP-131K was a 12 gauge shotgun. The tubular magazine had a 5-round capacity and the detachable magazine could hold 4 shells.
There were at least two reasons why it was sold for a very short time and then discontinued. First, strangely enough, it didn’t have high enough demand on the market. Second, it was pretty complicated to manufacture, especially the magazine.
To me, this system is incredibly interesting and could become something really useful and handy if it was further developed and refined. If they could make the magazine to be simpler and higher capacity that would be an outstanding defensive and combat shotgun. Imagine your main source of feeding (loaded with your primary ammunition – e.g. buckshot) are the detachable box magazines of 8 or 10 round capacity. That would give you an advantage of quick magazine changes compared to loading the tube magazine. At the same time, you could always have some secondary ammunition for different tasks (slugs, less lethal loads etc.) which you could switch to in a matter of turning the selector lever or by removing the magazine.
What do you think such a design could be useful for?