What best describes the difference between single-action and double-action firearms?

• A. Double-action requires manual cocking of the hammer or slide.
• B. Double-action fires after a separate hammer cocking.
• C. Double-action cocks and fires in one movement; many designs have safety.
• D. They are identical in operation.

Answer: (C)

The difference hinges on how the hammer is cocked and released when you pull the trigger. In a single-action firearm, you must manually cock the hammer before firing; the trigger just releases the hammer to strike, so the trigger pull is typically light. In a double-action firearm, one trigger pull cocks and then releases the hammer in a single motion, allowing you to fire without pre-cocking. Many double-action designs also include a safety to help prevent accidental discharge. Some guns blend both modes (double-action/single-action), where the first pull cocks and releases, and subsequent pulls are single-action with the hammer already cocked.

So the best description is that double-action cocks and fires in one movement, with safeties present on many designs. The other statements describe manual or separate cocking, or claim identical operation, which doesn’t capture how double-action works.