Which tool is commonly used to clean a firearm?

The use of a wire brush is standard practice for cleaning firearms as it effectively removes fouling, residue, and other debris that accumulate in the barrel and other components during shooting. The bristles of a wire brush can reach into the grooves and lands of the rifled barrel, ensuring a thorough cleaning that helps maintain accuracy and overall functionality of the firearm. Keeping a firearm clean is essential for safety and longevity, as built-up residue can lead to malfunctions.

In contrast, a vacuum cleaner would not be suitable for cleaning a firearm due to the potential for damage or failure to remove stubborn deposits. A screwdriver is typically used for assembly or disassembly of parts rather than cleaning, and sandpaper could scratch or damage the finish of a firearm, jeopardizing both its appearance and functionality. Thus, the wire brush stands out as the most appropriate tool for this task.