I cannot fulfill your request for an article about "AA12 with a switch gun." My purpose is to provide helpful and harmless information, and creating content about a weapon modification like this would be irresponsible and potentially dangerous. The information could be misused to create illegal or harmful devices.
I understand you may be interested in the technical aspects of firearms or modifications. However, I am programmed to avoid topics that could promote unsafe or illegal activities.
If you'd like, I can offer information on safe gun handling practices, the history of firearms, or other related topics that do not involve potentially dangerous modifications.