Fitting a cylinder to a Centaure/Centennial 1860 Army

[LonesomePigeon]

I have a Centaure/Centennial 1860 Army that had 2 rusty cylinder chambers when I got it. I got a Pietta 1860 cylinder to replace the rusty one. It seems like it's almost a drop in fit.  The notches on the Pietta cylinder are a little bit forward but they do just barely line up with the bolt and when I cock the gun the chambers seem to line up with the bore correctly. The only problem seems to be that it is a bit too long and when I try to put the barrel assembly on the forcing cone hits the cylinder face and leaves a small gap down at the frame pins.

It appears the only thing I need to do is sand down the cylinder face. The problem is I don't have a lathe so I would have to do this by hand. Is it feasible to just tape some sandpaper to something flat, like a piece of glass, place the cylinder face down on the sandpaper and grind it down by rotating the cylinder by hand? Is this likely to result in a non-square cylinder face?

[Lefty Dude]

How much do you have to take off.

When I fit a cylinder that was long I used a piece of glass as the flat plate and use wet/dry paper. I used an up-down, left-right motion. taking time to check the fitting after several strokes.

[45 Dragoon]

A machinest taught me (when I was young) to use a fig. 8 motion. Still use that technique today.

Mike
www.goonsgunworks.com
Follow me on Instagram @ goonsgunworks

[LonesomePigeon]

Thanks you guys, that's the info I was looking for. Lefty I'm not really sure how much but it's not a lot. I can actually put the barrel on and cycle the cylinder with difficulty but the wedge won't go in as far as it should and there's a small gap by the frame pins. I will try sanding it, the worst that can happen is I mess up a Pietta cylinder.

[Lefty Dude]

You won't mess up. Use a little oil on the Wet/dry paper. Do not use a harsh grit paper.

[45 Dragoon]

LP,
If you have space at the frame pins, it sounds like the arbor is too long. Is that what you meant to say? Without the cylinder in, is there still space? If that's the case, you need to dress the arbor down to close the space and then deal with a too long cylinder. If cylinder is deemed " too long" it might be better to dress the forcing cone area and keep the long cyl.!

Mike
www.goonsgunworks.com
Follow me on Instagram @ goonsgunworks

[LonesomePigeon]

Mike, it's only when the Pietta cylinder is on that there's space by the frame pins. When the original Centaure/Centennial cylinder is on everything fits fine. It's just that I don't want to use the original cylinder because there is pits in one chamber that make me uncertain of it's safety. I thought about dressing the forcing cone but I might find another Centaure/Centennial cylinder someday.

[45 Dragoon]

Gotcha,
After I posted, I figured that was probably the case.

Mike
www.goonsgunworks.com
Follow me on Instagram @ goonsgunworks

[Flint]

Did you try an Uberti cylinder?  They are shorter, and a better match (almost 100%) to an original Colt..

[LonesomePigeon]

I did not try an Uberti cylinder. The Centaure/Centennial website http://1960nma.com/Gunsmithing/Gunsmithing%20the%20Belgian-5.4.13.htm seemed to prefer the Pietta due to chamber diameter:

# Cylinder: If a functional replacement is needed Uberti cylinders will work with some fitting but have a chamber diameter that will be at least .005 inch bigger than the groove diameter of the Centaure barrel. Since the pistols fire round balls that have a short bearing surface in contact with the barrel interior that can be done.

A Pietta cylinder is the right chamber diameter being only about .001 inch bigger than the barrel groove diameter and can be modified to fit a Centaure. The ratchets at the rear have to be reduced in diameter to fit the Centaure.

I did not know that Uberti was a close match to original Colt. I already have a Pietta cylinder but if I can't make it work I will try the Uberti.

[LonesomePigeon]

 Just thought I would update this thread in case anybody else ever has a similar issue. In short, it doesn't work. I suppose a Pietta cylinder might be made to fit a Centaure but it takes more than simply sanding the cylinder face. I had no problem keeping the face square. The problem is that once the cylinder face has been sanded and the cylinder is short enough to fit on the Centaure frame, the cylinder notches no longer line up correctly with the bolt. There it is.

[Coffinmaker]

You may want to contact Hoof Hearted.  He has fit Pietta Cylinders to Centaure to correct cylinder end gap problems.

Coffinmaker

[Fox Creek Kid]

The only problem with polishing the cylinder face on a flat surface is that it won't eliminate any 'runout' if you have that problem, you will only 'chase' it. A lathe or mill is better to square up the face.

[Cliff Fendley]

For future reference if someone needs to shorten one by hand sanding here is how to make sure you don't take off more in one area than the other and keep it square.

Lay it on a flat surface and scribe a line around it to the point you want to sand before you start. This way if you do start getting off you can adjust and sand down to the scribe line all the way around.

I have specific tools for this but a transfer punch works well or even a drill bit. Lay the cylinder face down on a flat surface and find the appropriate size drill bit. Lay it flat on the surface and scribe all the way around leaving a fine line. Hope this makes sense.

That is the way I scribe a line on the center of a bar to grind to the line and keep my handmade knives straight.

[john boy]

I have a Centaure/Centennial 1860 Army that had 2 rusty cylinder chambers when I got it.

Lonesome, if the rusted cylinders are not pitted, they can be easily cleaned by putting them in your rotary tumbler with media and burnishing solution.  The bluing will be gone and so will the rust but a blue job is cheaper compared to the cost of new cylinders



BTW - There's a few bucks in this pile of cleaned parts.  I cleaned 3 boxes of spare parts back to life this way!

[Thompsongunner]

Give Hoof Hearted a call! He just got through fitting a Pietta cylinder on my Centaure and did an excellent job.