I had a toy pistol that used these and it would auto advance the roll, coming out of the handle, every time the chambers turned. It used to misfire about one out of every 7 or 8 so I used to take the "spent" portion an hit it with a hammer to pop them.
After you got bored with the cap gun after 5 minutes, your ears are probably still ringing after you smacked with the whole roll with a hammer.