"XL" was a brand name used by Hopkins & Allen to cover several different styles of revolver, but the first were a series of rimfire, spur-hammer pocket guns made in the 1870s and 1880. These were mostly very simple, chambered for a range of cartridges from .22 rimfire to .41 rimfire. Some examples of the .41 caliber XL-6 have a quite interesting feature, however. When the cylinder axis pin is removed, the cylinder swings out about 45 degrees to the right, propelled by a captive spring. This makes the chambers easily accessible for reloading.

This system was originally patented by Samuel Hopkins in 1862 and 1864 while working for the Bacon Firearms Company. Bacon made about 300 revolvers using this system, but they were shut down by a patent infringement lawsuit from Smith & Wesson, as their revolver used bored-through chambers without having a license from Rollin White or S&W. When the Bacon Firearms Company lapsed into bankruptcy its remains formed the start of Hopkins & Allen. Having acquired both the legal patent rights and the employment of the original inventor (both Samuel Hopkins and his brother Charles were partners in the new firm), it should be no surprise that Hopkins & Allen would use the system once the Rollin White patent expired. What is a bit surprising is that they did not use it more extensively…