Quote from: The_Shadow on May 09 2017 07:12:09 AM MDT
MatthewVanitas, my advice to you is to contact Case Reeder and discuss the project do ability, machining and cost.
His shop has done conversions for 10mm, 10mm Magnum already and knows what's involved.
http://www.reedercustomguns.com/

Also welcome to the forum!  Enjoy!

Happy to be here! I spoke with Reeder last year and his waitlist was up around a year at the time. I was also recommended to contact Hamilton Bowen, Dave Clements, and Alan Harton to ask for quotes. This would be after I nail down the semi-final design details.

Hello all, long story short I'm working out the details to have a custom sixgun made. Not going to be cheap, but I have a max budget of $2k so pretty sure I can pull this off. The goal is to be a "modern" Ruger-ified version of the old Colt M1877 "Thunderer" revolver. So similar in overall contours, but built on Single Six with adjustable sights (.32 donor gun), good modern steel and components, etc.

The original was in .41LC but I don't want to mess around with heeled bullets right now, and that cartridge was never famous for accuracy (though apparently an awesome up-close manstopper). I've talked with folks on a couple forums and the general consensus appear to be that a rimless 10mm cartridge is not a difficult conversion on a Single Six with a 5-shot custom cylinder, but it has to be moderate pressure and not compatible with off-shelf ammo that could damage the small frame.

I have an amazing name thought up, but the working code-name is ".402 Umptyfratz". The idea is to take a 10mm Magnum auto-pistol cartridge and cut it back to a length slightly shorter than the Mag but longer than the Auto. So if someone tries to load a 10mm Auto it'll fall too far into the chamber, and a Mag would protrude too far to chamber (since rimless cartridges in an SA revo headspace on the case-mouth).

10mm Auto: 25.15mm case length
10mm Mag: 31.88mm case length
Ruger Single Six cylinder: 35.30mm overall

My main goal is to load this with 220gr .400" cast bullets at sub-sonic speeds, though poking around online I've seen vague mentions of 230gr, 250gr, and even the odd mythical mention of 300gr 10mm cast bullets, so having some room to load the fatties would be cool. And as I understand it using a longer case rather than, say, a .40 S&W means I can have lower operating pressures.

I emphasize, this is just a fun plinking gun, I have zero desire to hot-rod it to try to take down a boar or whatever. I'm totally open to mild loadings, trying Goex, things like that. But I would like to err towards heavier bullets just for that satisfying "thump" and mine will have adjustable sights so even subsonic I'd like to try some of the old "Elmer Keith's mortar" and try to ring gongs at long-range with it, even if it takes a few seconds for the bullet to get there. 

I have experience loading .32 H&R but that's about it, and I just loaded them by the book, so don't claim any expertise in the actual physics of it. Anyone have any general comments about the feasibility of this project, factors to bear in mind, and sane load development practices I should follow?