How do some cops and some inside security circles spell backup? No, it doesn't start with a "b," rather, this definition for close-quarter backup-as in Compact Off-Duty Police-is spelled COP.

That's COP .357 for the uninitiated-and this bad boy is a real handful.

Law enforcement trains for any and all contingencies, highest on their list perhaps, the loss of an officer's primary service weapon. Whether the bad guy takes it; they run out of ammo; or the gun misfires, the odds are, those tasked with Serving and Protecting will one day have to rely on a backup.

Since Henry Deringer set the bar with his compact, .41 caliber, blackpowder, single-shot derringer in the 1800s, the name derringer has become synonymous with conceal and carry, close-quarter, hard-hitting handguns worth their weight in gold-notably when an officer's life is on the line.

It's true: Good things often do come in small packages. And historically, the derringer-whether it's a one-shot, two-shot, or multi-shot affair-is an effective choice for conceal and carry gun users.

Unfortunately, the list of those who have depended on such compact guns has not always fallen on the right side of the law-the good guys aren't the only ones that appreciate the derringers' worth. A rogue's gallery-from pimps and hookers to political assassins-have found the derringer irresistible.

The COP .357 is a unique 4-shot derringer designed by Robert Hillberg. He's the guy that brought us those way-cool insurgency shotgun designs-the Winchester Liberator and Colt Defender.

But that's another very interesting gun story.

Hillberg played around with manufacturers Winchester and Colt before, during, and after the Vietnam War. And during that period of small arms history, he developed viable, multi-barreled shotgun platforms for guerrilla and counter-guerrilla use that sadly never realized their full potential.

The COP .357 derringer stemmed from the poor showing of the Liberator and Defender and followed on the heels of an earlier weapons design-the pepperbox gun with its rotating barrel design.

But the top-break, COP .357 deviated from the revolving pepperbox design, in that it uses a rotating striker design, that can discharge four separate, albeit fixed, barrels. This gun's a real doozy.

A group from Torrance, California-COP, Inc.-manufactured the COP .357 Derringer. But no longer-the company went out of business. This double-action derringer is still around. It has the profile of a .25 ACP, but it's heavy, tipping the scales at 1 � pounds, empty. It shoots .357 Mag and .38 Special, and it is only about 5 1/2 inches long. The COP .357 is made of semi-matte stainless steel and checkered wood grips. Unlike its siblings, the COP .357 got slightly more respect than the Liberator and the Defender. For my money, the COP .357 is hard to beat when it comes to backup handguns.