Soumds plausable since there is no pressure curve as all the gas and powder is by passing the bullet. It looks about the same power level as a 2 3/4 slug. Definately not the same as when launched from a 50cal chamber and bore.
"Gun control: The theory that a woman found dead in an alley, raped and strangled with her panty hose, is somehow morally superior to a woman explaining to police how her attacker got that fatal bullet wound." L. Neil Smith
The problem with being stupid is you cannot simply decide to stop doing dumb things...