It started when I got my first .340 in a synthetic Mark V. The man that taught me all things guns and reloading already had a beast of a load worked out for the same rifle. So I loaded some up after the 3rd shot on what was going to be a 5 shot group.( the scope that was on it did not have enough eye relief.) I said this damn thing is going to put me in the emergency room . He laughed and said oh so you need a emergency brake pussy. And so the term was born.Lol I'll have to remember that.