Cas City Forum Hall & CAS-L

CAS TOPICS => Gunsmithing => Topic started by: reno on February 15, 2021, 01:56:39 PM

Title: How to rebate a cylinder on ASM 1860 Conversion
Post by: reno on February 15, 2021, 01:56:39 PM
Anyone have an idea how to rebate a cylinder on an ASM 1860 Conversion. As you know the cylinder on ASMs are not rebated. Would you and how? I was thinking of masking the cylinder just in front of the bolt notches and back from the scrolling and file a very shallow line around the cylinder and cold blue. Any thoughts?
Thanks,
Reno
Title: Re: How to rebate a cylinder on ASM 1860 Conversion
Post by: Professor Marvel on February 15, 2021, 03:50:25 PM
My Good Reno -
I am confused  ( as usual)
are you talking about making the cylinder fit a standard 1860 frame with the "stepped water table" ?

or something else?

yhs
prof marvel
Title: Re: How to rebate a cylinder on ASM 1860 Conversion
Post by: Abilene on February 15, 2021, 05:13:47 PM
Well, I'm not a machinest or gunsmith, but I'd think it would take a lathe to properly cut down the rear of the cylinder.  What you are describing sounds like it would simply make a line around the cylinder where the rebate would start.  On the other hand, I've seen a few pics of some ASM conversions that seemed to have a line there and it almost looked like they were rebated, though of course the frame was not stepped. 
Title: Re: How to rebate a cylinder on ASM 1860 Conversion
Post by: Sir Charles deMouton-Black on February 15, 2021, 06:08:40 PM
I'm not sure I'd want to change it from factory specs without reason. I understand cosmetic changes to make a more faithful copy of the original, but this is too close to the boiler room for me to contemplate the rebate you propose.

Colt had a gap in their model lineup. The 1849 was popular for "concealed carry. The 1851 was a popular belt pistol. The Dragoon was way too heavy for even a horse pistol. A new belt pistol in the dragoon caliber was desired, and possible with more modern steels. Colt made one prototype in the new configuration. Then, the lights went on!

With an 1851 frame made of modern steel, a barrel group in .44 could be made to fit without manufacturing a new frame size. As the new cylinder had to be wider for .44 caliber, a "shoehorn solution" was tried. Step down the rear so the existing lockwork could be made to operate, with a wider mouth for army size bullets. By golly, it worked. Add in the creeping rammer being worked on for the navy/ranger, and a classic was born.

I'm not sure what pistol you are working on. is it the incorrect 1851 Navy .44? If so, even with a rebated cylinder it would still be incorrect. Perhaps you could say that the .44 Navy was the lost production run of that one prototype?
Title: Re: How to rebate a cylinder on ASM 1860 Conversion
Post by: reno on February 15, 2021, 06:27:18 PM
Thanks to everyone. No I do not want to lathe down the cylinder, I just want it to look like a 1860 conversion cylinder. I know if you lathe down the cylinder the bolt would not connect the bolt lugs right. It is just for the looks, a light line around the cylinder for looks.
Thanks again,
Reno
Title: Re: How to rebate a cylinder on ASM 1860 Conversion
Post by: Coffinmaker on February 16, 2021, 08:59:54 AM

 :)  Ah So   ;)

Finally read far enough to understand what you wished to accomplish.  There is a base problem.  As I think you already know, the ASM Conversions were ALL built on a base 1851 frame.  The "1860" ASM conversion was actually built around the dimensions and look of an 1861.  The differentiation from an 1861 was to simply add an Army Pattern longer Grip Set.  No Rebate possible.

For the "look" you are seeking, it will take a Lathe, or Drill Press, or Drill Motor (clamped down) and a seriously solid Steady Rest to successfully make a small groove in the cylinder.  Understanding, you get that groove a few thou too deep and the cylinder will blow apart.  I find I cannot recommend the project for nothing more than a "look."  I'd be more inclined to find a Navy pattern Grip Set and call it what it is.  A "never never" Colt 1861 conversion.

Stay Safe Out There
Title: Re: How to rebate a cylinder on ASM 1860 Conversion
Post by: reno on February 16, 2021, 12:38:43 PM
Thanks Coffinmaker, I was just thinking on it and sometimes that can be bad. The revolvers are in really nice condition, and I am leaving them as they are. And thanks again to all for the help.
Reno
Title: Re: How to rebate a cylinder on ASM 1860 Conversion
Post by: Long Johns Wolf on February 17, 2021, 04:40:55 AM
In the early 2000s I owned one of these ASM R1s and a Uberti RM, both in .44 Colt
I seem to recall that the "inner dimensions" of the two cylinders - chamber to arbor distances - were pretty close.
Would it be possible to fit a Uberti RM cylinder to the ASM frame by removing some steel frome the watertable?
Just a thought.
Long Johns Wolf
Title: Re: How to rebate a cylinder on ASM 1860 Conversion
Post by: Coffinmaker on February 17, 2021, 11:38:29 AM

 :)  Hi L. J.

Possible.  Not really practical.  One would need to tear down to bare frame, load it up in a mill and carefully mill the forward part of the water table.  Especially as the water table is not flat.  While at one time when I still had my machine tools, I could do the job, I actually wouldn't.  Just isn't a good thing to do.

Makes much more sense to just go with a Uberti R/M in .44 and just fix the Barrel to Arbor fit. 

Stay Safe Out There