Very few were made and then Ruger stopped production. My understanding was that Ruger beveled the cylinder openings on the Mach2 cylinders for easy chambering, and this was allowing the case to back up upon firing, thereby jamming the cylinder and keeping it from turning.
I've had one on order since February. I have seen a few on the gun auction sites, but am leery now because of the problem. Instead of waiting or taking a chance, I bought a used 17HMR Single Six for $269 & ordered a Mach2 conversion cylinder for $100 from Brownells. It's blue instead of stainless, and doesn't have the scope mounts, but should do everything I want, and I came out cheaper than the "Hunter" model.
I haven't received the cylinder yet, I'll post my impressions once I get it.
