I guess this belongs here if anywhere. There is a company called Leinad that makes little black derringers somewhere in Tennesee. They make all kinds in many barrel configurations. Pepperboxes, over under, side by side, single barrled, even blackpowder versions. They also make a survival drilling based on their .22 over .410 derringer. It comes with 18 (i think) inch barrels and a folding stock that somehow clamps on the pistol grip. I have never even seen one of these in person before, so I am just describing it from a small photo in Shotgun News.
My question is, does anybody know if the .410 barrel is smooth bore or not? All of their .410 derringers have a rifled barrel and a .45 colt/.410 combination chamber. This is one of the few firearms they make with a barrel over 18 inches, so I am wondering if they rifled the .410 barrle and put a combination chamber in it like they do their derringers, or if they just made it a smoothbore .410. I believe the barrel is 18 inches, it might be 16. If it is sixteen I guess it must be rifled, but I just don't know how long it is. I suppose I could send an e-mail to the company selling them. I was hoping somebody here might have one and be able to tell me something about them.