The legal risks of shooting someone with a load of birdshot, even if they are trying to rob you at gunpoint — in today’s environment, thugs pulling such stickups might be more prone to pulling a trigger as well — are more in the sandbox of our own Massad Ayoob, or a good criminal defense attorney. There could be all sorts of ramifications, depending upon the prosecutor and your state’s self-defense statute.
A snakeshot load is not a frangible bullet. It is a payload of tiny lead shot pellets held loosely inside a hard plastic shell, whereas a frangible bullet is, according to one definition, fabricated from “mixtures of powdered metals” such as copper, zinc, tin or tungsten, resulting in a compressed material which can be made to form projectiles, “with or without jacketing.”
I have also tested projectiles consisting of bullet jackets filled with tiny shot held together by some sort of resin. They open up almost immediately upon penetration and create wound chaos.
To my knowledge, the businessman’s strategy was never put to the test, and I don’t recall having ever encountered anybody else who loaded a defensive revolver in such a way. Today, most people opt for a semi-automatic, anyway.
In some jurisdictions, a prosecutor might conclude the would-be robber initiated the event and shooting him, even with a load of shot, would be considered justified. Elsewhere, one might find himself or herself on the wrong end of an indictment, followed by a civil lawsuit even if acquitted.
Of course, the risk you only wound someone enough to guarantee they would want to leave you dead is a major consideration. Fifty years ago, it seemed like a good idea to a small-town retailer who, a) was determined to fight back, and/or b) didn’t want to be murdered for whatever small amount of cash might be in his register.