Complex sentence: The Hinawa Revolver was an early Japanese handgun of the Edo period used by Samurai troops and was invented around the same time, or before the Americans and Europeans were in the process of manufacturing multi shot firearms.
Split into simpler sentences: The Hinawa revolver was an early Japanese handgun of the Edo period used by Samurai troops. It was invented around the same time, or slightly before the Americans and Europeans began manufacturing multi-shot firearms.