Single-shot breech-loading rifle. Chambered for .54-caliber. Utilizes percussion ignition system. Breech opens for loading by lifting and pulling back on a lever. Barrel 33" in length. Full-length walnut stock held on by two barrel bands. Mountings and patchbox are brass; lock is case colored, with browned barrel. Lock marked "J.H. Merrill Balto./Pat. July 1858". There are military acceptance marks on stock. Approximately 775 of these rifles manufactured and purchased by government for use during Civil War. Made in 1864 and 1865. Values are for Civil War rifle. Hunting percussion rifles with Merrill markings bring less.