What it is!

Powder Measure c. 1700’s. The larger end would have been inserted in a powder horn. The lever manipulates two gates within the measure. When the horn was tipped, the first gate allowed powder to run into the measure. Then the second gate was closed so that the measure could be fitted into the muzzle of a flintlock. The first gate was opened and the measure of powder ran down the barrel while the second gate kept the rest of the powder in the horn from also running into the gun.