It served me well for a long time, years. Until I finally found out how they were originally made with a wood base plug. Then I made a new one.
It never did leak and is still the same as the day it was made.
This is the third horn I made. I would like to take some images of my second powder horn, but there is a bee hive right on top of it in my old workshop! The bees gather all around me when I go into the workshop but have never stung me to date, but I think that if I tried to extract my powder horns from under their hive, they are likely to attack.