When the slide is fully forward, what is the first step in the immediate actions procedures for the M-9 Pistol?

The first step in the immediate actions procedures for the M-9 Pistol, when the slide is fully forward, is to ensure that the decocking/safety lever is in the fire (up) position. This step is crucial because it prepares the pistol for firing. The decocking/safety lever is designed to either engage or disengage the safety mechanism, and positioning it correctly allows the shooter to fire the weapon when ready.

This procedure assumes that the firearm has been properly handled and the shooter is in a controlled and appropriate environment to discharge the weapon if necessary. If the lever is not set to the fire position, the pistol will not fire, which could lead to confusion or delay in a critical situation.

In terms of the other steps listed, while ensuring the magazine is inserted and cycling the slide are important aspects of handling the firearm, they follow after confirming the decocking/safety lever's position. Checking that the safety is on would be relevant if the intent is to ensure safety before performing other actions, but for immediate readiness to fire, the lever position is the top priority.