In Part 1 we discussed the anatomy of a jam. Here, we point out what to look for and what remedies might solve your shotgun malfunctions.
Read Part 1 of this series here: Semi-Auto Shotgun Malfunctions: Part 1
The rearward movement of the bolt relies on the energy from the fired cartridge. If the cartridge does not create enough energy to move the bolt and overcome the counter-resistance, the action will not cycle completely and a malfunction will occur.
On the contrary, if the bolt moves too fast, the other systems within the action may not be able to keep up and again a malfunction will occur.
You have to match the cartridge to the gun. In other words, if your gun was made in the era of paper shotshells, or when heavy "dram" loads were all the rage, you need to replicate the same amount of energy from the ammo you will feed it today for it to work properly. If your gun was made when shotshell velocity was typically between 1,100 and 1,300 feet per second and you are using modern non-toxic shot with velocities in excess of 1,500 feet per second, you should not be surprised if you gun is malfunctioning.
Some actual examples of customer complaints of malfunctions include an inertia operated gun and a long-recoil system gun that would not cycle when the owners attempted to use light-recoil target ammo. In another case, a short-piston action gun was loaded with shotshells that had a listed velocity of 1700 feet per second and a variety of malfunctions manifested.
Fixing the Problem
To return the bolt forward, a spring is the most common way to provide the force. The spring can be located in the stock behind the bolt, or it can be located in front of the bolt where the bolt rides on "action rails." In some cases, there is a combination of springs both behind and ahead of the bolt that are pushing or pulling it forward and back into battery.
The short story on springs is that they have an operating force that is expressed in pounds, they "take a set" - that is, they wear in to a point that they return to after compression, they have a "rate of return" or a speed in which they compress and expand, and they can lose force over time.
The return spring in a semi-auto shotgun needs to be compressed enough by the rearward movement of the action to generate enough force to drive the action closed all the way. It also must do this at just the right speed to allow the next cartridge from the magazine to be picked up by the lifter and put in front of the bolt for feeding.
If your semi-auto shotgun is malfunctioning, you should start with a good cleaning. Eliminating resistance through clean and properly lubricated parts may solve any issues.
Next, inspect the parts. Make sure the ejector and extractor are in place and not broken, and that the magazine follower is pushing a cartridge into position for pick up.
If everything is clean and in good order, experiment with different ammunition by trying different weights of shot content and different velocities. If the problem persists and you are still experiencing jams, replace the springs and reassess what is happening.
If you cannot solve the problem on your own with these simple steps, it is time to get an assessment from a shotgun-smith or the manufacturer.