I have never seen a single act revolver with a swing-out cylinder. I presume there is a reason for this. Does anyone know what that reason is? Thanks for the help.
My thoughts on the matter: It all comes down to timeline. SAs came first before SAs, when there were limitations on ammunition, machining capacity and tolerences, and metallurgy. The design of a SA was generally speaking kept as tough and simple as possible for these reasons. SA technology moved from cap-and-ball to metallic cartridges in th mid-to-late 1800s. As technology advanced, new designs were tried. Among these were swing-out cylinders. Yes, there were a small number of SA revolvers with swing-out cylinders. However, by the time the idea of swing-out cylinders (or top breaks, for that matter) became more mainstream, the DA revolver was already the state-of-the-art and the SA revolver was on the way out. Consequently the new swing-out/top-break technology was applied to the newest DAs rather than the "old" SAs. Incorporating a swing-out or top-break design to a standard SA revolver of the period would have required a few significant design changes; notably redesign of the axis pin and in many cases enlargement of the frame to accomodate the swing or break mechanism. It wouldn't have been a matter of simply adding a hinge.
I believe the top-break preceded the swing-out by several years. These automatically ejected the spent cases. The S&W model 1 was introduced in 1857 while the S&W "hand ejector" (swing-out cylinder) came out in 1899.
The first swing-out cylinder revolver was "Moore's Patent Revolver", produced from 1861 to 1863. It was single action only. The first swing-out model to see widespread success was the Colt M1889, which as the name implies was introduced in 1889. The SW Hand Ejector was a greatly improved design, but postdated the M1889 by a few years. Break action revolvers are not a primary area of interest for me, so take the following with a grain of salt. The first top break revolver was (I believe) the Smith and Wesson Model 3, introduced in 1868. The Model 1 was a "tip up" revolver (the pivot was mounted on the top of the frame rather than the bottom, so the revolver broke open and the barrel hinged upwards and towards the shooter, instead of hinging downwards and away from the shooter in a top break design). The Model 1 was introduced in 1857.
