Dictionary.net

Small wooden cases covered with leather, each containing powder sufficient for a charge; the shoulder-belts worn by anc. Musketeers : bandog, a kind of large dog; a mastiff.

Small wooden cases covered with leather, for holding the charges of a musket, and suspended from a shoulder-belt. [Fr.].

Small wooden cases covered with leather, each of them containing powder that is a sufficient charge for a musket.