I never had a Colibri stick in a bore. I just recall reading the warning. I did notice that they chrony slower out of a rifle than they do out of a pistol. That caught me by surprise. I think that they were about 380fps out of the rifle. My pellet gun is much faster than that. The CCI & Remington CB caps were faster too. Off the top of my head, one of them was around 750fps. I can't remember which one. It's been a while now.