A gun barrel cleaning tool includes a handle, a lock member connected to the handle, a barrel-shaped cleaning element having a fixing portion that is rotationally fixed to the lock member so that the fixing portion of the barrel-shaped cleaning element is rotationally fixed in both directions relative to the lock member, and a cleaning element having an engaging portion in rotation locking engagement with a part of the lock member so that the engaging portion is rotationally fixed in both directions relative to the part of the lock member. The cleaning element includes a cleaning portion whose outer diameter can be varied to clean gun barrels of different gauges.