An auction in August has an old percussion breechloader. Best description is a falling block type action, about 50-55 caliber. Overall size is about like 1873 Springfield carbine. Breach block is hinged on right. Bullet and powder are dropped in, then breechblock is swung down in place, percussion cap placed, ready to fire. Only mark is FJ. Never saw anything like this. I wonder about gas escaping back into the shooters eyes!