"The Brass Barrel Rifle" [dated 1771]
This rifle is pictured in Rifles of Colonial America, Volume II (#103). George Shumway failed to mention that is is dated in two places 1771. That makes it the earliest known dated rifle with a brass patchbox. There are others that are probably earlier but they are not dated.
George shows many views of this rifle so I'm only posting close-ups of the lock and the dimensions of the barrel.
The cock is an in use replacement from an English style lock of about
1790. There is no way to tell when it was added but there is evidence
that the rifle continued to be used with this cock. The original
Germanic style cock would have been engraved to match the plate.
Having the main spring attached by a blind screw (one that doesn't go
through the plate) is unusual.
The original brass barrel was cast of brass. At some point it was bored
smooth, probably for shooting shot, and the walls were very thin in the
smaller section. There was also a lug for attaching a front sling swivel
dovetailed into the smaller section of the barrel. At some point the
tube was broken at that attachment point. Amateur attempts to braze the
barrel did further damage and left no choice but to replace the damaged
section. The original length was determined a closely as possible by
measuring loop placement and marks on the bottom flat showing pipe
placement.