Little known fact that this is what we call a 'bootstrap paradox' and Eugene Stoner was a time traveller. A bootstrap paradox is similar to a temporal paradox except it is sort of in reverse. Eugene travelled to the future in which he had already invented the rifle about which we are speaking. In the future, he copied the rifle. Then he travelled back to the past and 'invented' it.
That is the way I have always heard it anyway.
That is the way I have always heard it anyway.