When it happened to me, I simply tried pushing it in further (but not so it gets stuck). Make sure to be careful as when it got stuck, I had to use tweezers and it ripped the plastic off the top. I had to buy new ones but I also agree with Jay s as usually they're just worn out so my method will work but after a while the bullet will get so misformed it won't work and the bullet will be a piece of junk taking up space.