It happens mostly when you load the rifle and release the bolt after loading the magazine and don't get your thumb out of the way fast enough. You know real authors do years of research about the subjects they write about, they don't just go on a message board and ask questions from people who may or may not know what they are talking about. That is not aimed at Jack Ryan but there are plenty of people on message boards who if they do not know something they will guess and just make it up. You are not doing research, you are doing a shortcut, putting together bits and pieces of things you do not understand told to you by others. How can you expect to write about things you don't even understand and end up with something worth while?