What must be done once the weapon is assembled?

Once the weapon is assembled, performing a function check is essential to ensure that all components are working correctly and safely. This procedure involves verifying that the weapon cycles properly, that all parts are functioning as intended, and that there are no issues that could lead to malfunction during operation. A function check helps to identify any potential problems before live firing, ensuring that the weapon operator can trust the equipment in a combat or training scenario.

While cleaning the weapon is important for maintenance and longevity, and loading ammunition is necessary for operation, these steps are not the immediate actions that follow assembly. A safety briefing, although critical for overall operational safety, does not pertain directly to the operational readiness of the weapon itself. Conducting a function check is the crucial step that directly assesses the weapon's readiness for use.