What is the function of the receiver assembly on the M249 AR?

The receiver assembly on the M249 Automatic Rifle serves as a critical component that supports the operation of the firing mechanism. It houses essential parts that are involved in the firing process, including the bolt and the trigger mechanism. This assembly ensures that the components can function together effectively, allowing for reliable operation during firing.

In this context, the receiver assembly plays a central role in connecting the various mechanical elements that work in unison to fire the weapon. Understanding the function of the receiver is essential for maintenance and operation, as it directly impacts the reliability and efficiency of the firearm.

Other functions mentioned in the options, such as housing the barrel or feeding ammunition, while important, are not the primary functions of the receiver assembly. Instead, those functions are fulfilled by different parts of the M249, further delineating the specialized role of the receiver in the overall operation of the weapon.