Bronze, copper, brass
American flask designers routinely borrowed ideas from European manufacturers. The unique gun stock design originated with James Dixon & Sons in Sheffield, England but was adopted by the American firm of Frary, Benham & Co. by the 1850s. Flasks by that Connecticut-based company were nearly identical to those made by Dixon. The only major difference was that flasks by Frary, Benham & Co. were slightly larger. This flask is able to hold eight ounces of powder. After Frary, Benham & Co. was bought out in 1857, its successor company, the American Flask & Cap Co., continued to produce this design.
Gunpowder was sold in bulk and gunpowder flasks were used to carry gunpowder when out in the field.