Are single action and double action fire mechanisms considered the same?

Single action and double action fire mechanisms are indeed different systems, making option B the correct choice. The fundamental distinction lies in how the internal mechanisms operate to prepare the firearm to fire. In a single action mechanism, the hammer must be manually cocked before each shot, which means that pulling the trigger only releases the hammer to fire the round. This design results in a lighter trigger pull and is often found in traditional revolvers.

In contrast, a double action mechanism allows the trigger to perform both the cocking of the hammer and the release in a single motion, which results in a heavier trigger pull. This type of system is commonly found in modern revolvers and semi-automatic pistols, offering a quicker follow-up shot without the need to re-cock the hammer manually.

The differences in the operation of these systems significantly affect the user experience, safety considerations, and shooting technique, which is why they are recognized as separate mechanisms. Understanding these distinctions is crucial for proper firearm handling and operation.