Letter Re: An Interesting Extra High Power 12 Gauge Single Shot Shotgun

Dear Jim,
I found an article about this custom 3-3/4-inch 12 gauge, with energy exceeding that of a .50 BMG. It has extreme power, for very large game or certain anti-armor applications. It’s legally a shotgun, and easier to reload than rifle cartridges. Also, custom projectiles are easier to make. Some of the conversions are on readily available single shot receivers.One advantage is that the converted shotgun will still shoot all standard 12 gauge shells [of shorter lengths.] – Michael Z. Williamson