It's not a myth.
It happens.
I can produce it at will but don't since I'm not "into" blowing guns up.
There are more than one way to get the result, which I long ago resolved not to write about, because as sure as shootin', some nitwit would blow some fingers off just trying to prove me wrong. I frequently warn about these unwise loading practices, of course, but I don't present them as causes of the "SEE" or mention them in discussions of the "SEE."
The simplest way to put it is that you don't have to worry about the "SEE" if
(a) you don't try to wring the last possible foot/second of muzzle velocity out of your gun
and
(b) you always use ninety to a hundred percent of a case-filling charge of your optimum powder (which may not be your personal favorite and may not be listed in your manual).
