Colt open-top hand channel in frame: how is it cut?

[okto]

Hey y'all. I'm working on building a Colt Walker replica from scratch. So far all the machining operations are within my ability, but I'm absolutely stumped on how to cut the channel the hand rides in. It's a square-sided blind hole that pierces the face of the recoil shield in a way that doesn't follow the channel walls.

It looks like a feature that would have to be cast in--did original Walkers have cast frames? Are modern repros cast? There are a ton of reasons not to cast steel, although I suppose that would give additional cause for case-hardening the frame.

[Der Gebirgsjager]

Hi--welcome to the forum. Nobody here was likely around when the original Colt Walkers were being produced, although some of us feel like we were! Humor aside, based on the technology of the time, the channel was likely the result of drilling, and then shaping the round hole to square, perhaps with a file. They probably developed a jig to hold the frame at the desired angle to the drill bit. Cast steel frames were beyond the abilities of the day, and although there were doubtless early experiments by others, it was Ruger which brought them into mass production in the mid-20th Century. There have been several companies, most of them Italian, that have made Walker replicas and I believe that most of them were forgings, although one possible exception might be Pietta, which company has made cast frames.

[45 Dragoon]

Okto, looking at originals ( 1860 Armys) they were drilled then filed (as DG suggests). They looked fairly rough but the fore and aft surfaces were flat.

If you'll Google "making a single action revolver from scratch", you'll find a series of videos (15 I think). The young lady does a nice job of doing just that!! You will be interested in the last few minutes of the 3rd video.

Mike

[okto]

Thanks for the responses, y’all. Sounds like some skinny pillar files are in my future!

[country gent]

You might be able to make a broach and cut it in from the drilled hole a thousandths or 2 a time with the mill spindle. In reality they could have been filed, broached or cut in with a shaper. For your one off careful work with the fie is probably best.
To broach it a drill blank ground square with relief on the face to make a single edge push cutter. Locked in the spindle and the spindle locked then feed .001-.002 per stroke of the spindle till its where it should be. You cant take heavy passes since your arm is the power here. We cut small blind keys this way in the lathe.