Which of the following factors does NOT affect the burst of fire?

The factor that does not affect the burst of fire is the skin thickness of the shooter. Burst of fire refers to the pattern and effectiveness of rounds fired during automatic or rapid-fire engagements, and it is influenced primarily by variables that impact accuracy, control, and environmental conditions.

Clarity of target, air and weather conditions, and the gunner's skill level all significantly influence how effectively a weapon is employed. Clarity of target affects how clearly the shooter can aim and adjust their fire accordingly. Air and weather conditions, such as wind and humidity, can alter the trajectory of bullets and impact the accuracy of the fire. The gunner's skill level is crucial; more experienced gunners have better control over the weapon and can manage recoil and aiming faster, leading to a more effective burst of fire.

In contrast, the thickness of the shooter's skin has no direct relation to how well a burst of fire is executed; it does not impact the mechanics of shooting or the performance of the weapon itself.