The American Derringer Co. (ADC) "pen pistol" is a rather unusual single shot handgun that, "transforms from a 'pen' to a legal pistol in 2 seconds," according to factory literature. Introduced at the 1992 SHOT show, it was finally marketed in .25 ACP in 1993 or so. In 1994 ADC, which had been marketing this gun decided to stop, and it is now marketed by R.J. Braverman Corp. (which also has the patent on the gun, #5,062,231) who also added .22LR, .22 mag and .380 calibers to the lineup. They also started calling it the "Stinger." The actual manufacturer was and is Remcon North Corp. of Meredith, NH. I don't know why ADC stopped marketing the gun, but I suspect it has to do with its design and possible use. Simply put, this is a "naughty" gun, it is designed to beat the rules about what constitutes an "Any Other Weapon," (AOW) under the National Firearms Act. For more depth on NFA issues check out the faq on class 3 weapons. Simply put, any firearm that can be concealed on the person, and is not a conventional pistol or revolver, is an AOW, and is regulated like machine guns and silencers, among other guns, by federal law. The AOW category includes gadget or disguised guns, pen guns, cane guns, belt buckle guns, flashlight guns, stapler guns, alarm clock guns, the list goes on and on. The "pen pistol" looks like a pen gun, it is a cylindrically shaped, all stainless steel item, looking vaguely like a tire pressure gauge. It even has a pocket clip, like a regular writing pen. It is 5 1/2" long, about 1/2" in diameter, and weighs 5 ounces, unloaded. But as it cannot be fired in its closed, straight position it is not an AOW. In its firing mode the gun meets the rules for a pistol, it has a grip angled to the (rifled) bore, designed to be fired with one hand.
To fire the pen pistol you must insure it is cocked, by opening the gun. To form its "grip", and to make the spur trigger pop out of its recess you open it up, by pulling the two ends apart until they may be set at an 80 degree angle to each other. With the gun cocked, and the safety on safe, you may unscrew the barrel and insert a single round. The gun may be open or closed to load it. When you wish to fire it must be in the open position, and the safety must be on fire. The safety is a metal collar just behind the barrel, that twists from safe to fire. It is always on safe when the gun is closed. Push upward on the spur trigger to fire it. To re-load you must close the pistol, then open it to recock it, then you may remove the barrel and push out the spent shell, with it open or closed. Whether it is open or closed, the safety must be on safe to get the barrel to unscrew.
The sample I evaluated was an ADC one in .25 ACP. I fired 3 rounds out of it. It is pretty hard to shoot, the "grip" tends to twist in my hand, making shot placement hard. There are no sights. The trigger pull is pretty heavy, I did not measure it precisely. However when I got the thing pointed in the right direction, it hit the paper where I was aiming. You have to be very careful with this gun to keep your hands out from in front of the muzzle. It is very nicely made, the stainless steel has an attractive brushed finish, and the gun fits together quite nicely.
The question may arise, what is this gun for? It is too hard to get into action to be much of a serious back up, you need a lot of warning to unfold it and get the safety off, assuming you carry it loaded, which the manual strongly discourages. Plus a reload is unlikely. It isn't much of a target gun, with no sights and a grip that is hard to control. I think this gun is a tribute to the ingenuity of designers who can beat any silly law designed to curb unsporting or "bad" guns. This gun is really for someone who wanted a pen gun, but didn't want to do the paperwork to get, or lived in a state that prohibited, AOW's. It retains 99% of the disguise and concealment of a real pen gun, you just have to manipulate it more to shoot it. It is a nice piece of machining and engineering, which might be reason enough. It is a collector's item, in my opinion. Which is also what most NFA pen guns are as well.