100-300 USD
200 or so
100-300 USD
Revolver
75-260 or so
About $150-250, depending on condition, blued or stainless, etc.
In stainless, and in New in Box (NIB) a Ruger Speed-Six in 9x19 is worth $1,000+ as of 2010. In stainless, and in like-new condition, a Ruger Speed-Six in 9x19 is worth $700+ as of 2010. The 9x19 version of the Speed-Six is quite rare in the U.S. since only a few were sold in the US from European and Israeli military/security contract overruns.
A revolver designed for a revolver cartridge cannot, but some revolvers are designed to fire rimless cartridges. S&W and others made revolvers in .45 ACP, the Ruger Speed Six/Security Six was available in 9mm Parabellum.. they use full or half moon clips to hold the rounds in place and load the cylinder, rather than the traditional method of loading a revolver.
Ruger speed six's are selling between $200 & $275 depending on the condition. I just repurchased for $200 a .357 speed six that I originally bought in 1983, I believe that's what I paid for it new, it's had less than 1 box of ammo fired in it but you're unlikely to find one in this condition. Gunsmiths report that they have never seen a single six that was worn out but if you need new bluing you should consider paying less.
The Ruger web site has sn data if you can get to it.
1968 - 1988.
Yes
Model numbers 117 vs 207 and external physical features