How many major component groups does the M9 service pistol have?

The M9 service pistol has three major component groups, which are essential for understanding its operation and maintenance. These groups are the frame, the slide, and the magazine.

The frame serves as the foundational structure of the pistol, housing crucial internal components, such as the trigger mechanism and the grip. The slide is the moving part that houses the barrel and the recoil spring, allowing for the cycling of ammunition and ensuring proper function during firing. The magazine, which is removable, is responsible for storing and feeding ammunition into the chamber of the pistol.

Recognizing these three groups helps users of the M9 service pistol to better comprehend its assembly, disassembly, and overall mechanics, facilitating proper handling, maintenance, and troubleshooting.