barrel explosion

I was using this link to learn how to make an explosion, but my is without fire.

http://www.youtube.com/watch?v=PDGUaw0XrDg

I imported the barrels and then chose one which the bullet is going to reach.

I selected Partical system and clicked on PArray. Then clicking on Pick the object I selected the barrel and selected Mash. I went to particle generation and changed some parametres there (like the tutorial shows). On partycal type I selected object fragments and changed the number of chunks to 50. Later I went to Rotation and collision and changed some parametres there as well. Going to Helpers I selected Atmosphering aparatus and sphereGizmo. On Modify I added Free effect and changed some numbers on setup selecting explosion. I clicked the right click of the mouse and chose to hide the object ( the barrel), so now thw animation with exploasion was done.