Wyoredman,
The revolvers based on a fixed-cylinder single action setup are usually a clone or near-clone of the 1873 Colt SAA. Ruger's single actions (Blackhawk, Vaquero, New Vaquero and Single Six) are all "loose SAA replicas" with features like coil springs, modern safeties and in many cases improved sights grafted in. The fixed-cylinder system does have theoretical accuracy advantages. The most accurate revolvers in the world are either custom rebuilt Ruger single actions or from the facWyoredmantory, the Freedom Arms revolvers are the best out-of-the-box accuracy you can get, with some specimens dropping all their rounds into one inch at 100 yards - in other words, rifle-grade accuracy.
Being a complete lunatic in some ways, I set about trying to seriously improve the firepower and reload speed of the 1873 type guns. What I came up with is "Maurice", a Ruger New Vaquero re-chambered to 9mm Parabellum and rigged up with automatic gas-powered empty shell ejection and magazine feeding. Yeah...you read that right. It's called Maurice because some people call it the Space Cowboy
. I also severely upgraded the sights.
I carry it with five rounds in the cylinder plus two in a short "carry magazine". Once those seven rounds are downrange I can switch to foot-long 9rd magazines. I could, if I wanted to, stack 9rds in a long mag on top of five in the cylinder, but it would be ungainly at best in the holster
.
So far this feed cycle hasn't been used on any other personal weapon that I know of, handgun or rifle. And yes, it could be done to a DA gun with or without a swing-out cylinder, or even to a gun that started life as a swingout but gets converted to fixed because with Maurice's feed cycle the swingout isn't necessary for reloading any more. It basically represents a direction that the industry could have gone in circa 1890 or so, but didn't, opting to switch to semi-autos instead.
http://thefiringline.com/forums/showthread.php?t=511297