I have been waffling about having a custom single action built for several years now. Every time I thought I was ready to do it something shiny would catch my eye and there went the money but I decided it was now or never and have now finalized the details with John Powers and will be sending off a Ruger Old Model Flattop Blackhawk in .357 Magnum for him to work his magic on. John is going to rechamber the cylinder to 10mm and fit and chamber an extra cylinder to .38-40 and give it a BP chamfer, install a
5 inch octagon barrel and mark it .38 WCF/10mm, install a Fermin Garza front sight with interchangeable blades, Barrel length steel ERH With a Crescent ejector rod, a Brass Bisley Grip frame from Ronnie Wells with a Bisley Hammer and trigger, a Belt Mountain base pin then an Action Job and Free spin pawl. He is going to Case harden the frame and hammer and blue the cylinder and barrel. I am going to have
Scott Kolar fit either either fancy Walnut or Ivory grips to it. It will ride in a Barranti Keith No 5 holster. I can't wait!

Sounds like an awesome project gun!

Stupid question... 

Given that the cylinder is long enough and a Blackhawk can handle the oomph, why not do the 10mm cylinder in 10mm Magnum (rather than 10mm Auto)? 

See the thread on converting a S&W 610...

I have a crap ton of 10mm ammo and the .38-40 is a 10mm Magnum I'm easier to obtain brass. I can also have cylinders made in .40 or 10mm Magnum if needed later

I'm not arguing, just thinking at the keyboard... 

If you were to have the other cylinder chambered for 10mm Magnum, then you can shoot 10Mag, 10Auto, AND .40S&W:  All use the same moonclips. 

Starline sells new 10mm Magnum brass...

Moon clips aren't used in single actions so each cylinder only works for one cartridge.

Before pic

Quote from: pacecars on June 24 2020 05:53:05 PM MDT
Moon clips aren't used in single actions so each cylinder only works for one cartridge.

Why not?  If you're having a cylinder custom reamed and timed, then it seems like cutting it for moon clips would be a cinch.

Also, how are you going to extract 10mm if you're not using moon clips?  (Yes, you can poke them out with a stick, but that sucks.) 


Again, I'm not arguing;  I'm trying to learn...

Single actions are poked out with a "stick" so to speak. Rounds are loaded one at a time through the loading gate and then ejected one at a time with the ejector rod that is attached to the barrel There is no way to load a moon clip. I am guessing you have never handled a single action? Go to a gun store and ask to see a single action and get hands on and you will see

Oh, duh, now I get it... 

Yeah, I've shot a Ruger Single Six. 

You must be very patient.  (I'm not a patient person, and I found it tedious!)

New to Forum...  I came across a Vaquero in 10mm, Model No. KBNV-38X-C, 38/40, 40S&W, 4-5/8' barrel at a Ft. Worth Gun show in Nov 2020  It was made for Davidsons and sent there with simulated Ivory Grips by mistake instead of rosewood grip panels.

here's one I came across: Model KBNV-38X-C, .38/40, 40S&W bored to 10mm

I also ordered a Taylor's & Co Cattleman in .38-40 and bought a spare .357 Magnum cylinder and am going to send it off to Alan Harton to bore it out to 10mm and add a new front sight and a S&W J frame sight on the rear