The barrel plays the explosion animation before re-activating Q.
Also, the barrel is invisible until you re-activate the Q to trigger the explosion and then it replays the normal barrel animation until it bursts. Even after the sound effect stays.
Post your PBE bug reports here: something not functioning as intended? Store is broken? A champion's ability is not working? etc
Need help? Read our [bug reporting guide](http://community.pbe.leagueoflegends.com/c/bugs/CF5EEDC8FF5AC1A896F517E2C7AE4650C472807F-how-to-report-bugs-on-the-pbe).
Comments about things you don't like or suggestions for improvements go in Feature Feedback.