Gunpowder question, what am I doing wrong?

I'm making little cannons for fun. I bore a hole in it and then put a hole for the fust, i put the fuse in, put in the gunpowder, then pack it down and put the ball or whatever i'm using.. light and all i get is a fart of fire out the barrel.. nothing cannon-ee at all.. I'm using the gunpowder from a shotgun shell.. is that not right, weve had em for a couple years.. is there such thing as expired gunpowder?