Dispensers will fire once then wont fire again until the redstone is redone for them.

I was working on a compact rifle cannon for a ship that me and my friend are working on. I was testing it for any faults when I found the bug. The cannon will fully fire the first time but the second time the chamber dispensers wouldn't fire whilst the barrel dispenser would causing it to self destruction. The only solution I have for a build this small is to redo the redstone for the chamber dispensers. I have tested it in single player just in case it was a server issue but the big is still there. The cannon is required to be small due to the lack of space it has.