Can my 1860 be bored to 44 Colt?

[Hoof Hearted]

This is one of the most commonly asked questions in the conversion realm and since I try to explain it over the phone and via forum replies at least once a week I have decided to ATTEMPT to make it easier to understand with pictures, measurements and a whole lot of typing

If this is a WANT of yours, read on............

Below is a photo of a Real Colt cylinder of the second gen variety (in other words, same as Uberti):



If you look at the area between the chambers and the arbor hole that dimension is approx .055". That same dimension will hold true at the breech end after cutting off the back portion of the cylinder for the ring and boring straight though (because everything is parallel to the centerline).



The above Italian cylinder has been turned down to enter a conversion ring but has not been bored through. notice how small the ratchet teeth are?

[Hoof Hearted]

So now when you bore through the chamber and out that end and then ream for the 44 Colt chambering and the rim of the case (.482 diameter) you decrease the ratchet tooth width (the portion that the hand or pawl engages to turn the cylinder) to .0395". The picture below will help illustrate that:



This is why Colt made new cylinders with the ratchet tooth moved from the centerline of the chamber seen below:



To BETWEEN the chambers as show below on this original Richards cylinder:

[Hoof Hearted]

Of course this necessitated a longer hand (or pawl) with two stages and removal of the front face of the recoil shield.

The first design was the Thuer and since the cartridge did not insert from the rear the ratchet area could be left much larger! Enough material could be left for the pawl to rotate the cylinder without modification. The Thuer was the original, "drop in", conversion!

Here is a picture of the back of an original Thuer cylinder:



I hope this helps ya'll understand why the original cylinder won't work.............

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[Hoof Hearted]

Here's my thoughts on the design and genesis of the Colts revolver:

1851 Navy came first in 36 calibre.
Then more power was needed so the frame was rebated, cylinder enlarged (where it could be allowing the frame to use all the same geometry and parts). This was fine in concept for loose charges as the additional material in the front section of the enlarged cylinder gave added strength so larger barrel design and away we go for about 10 years.

I have heard it said that Samuel was a negative Nancy about cartridge pistols and shunned Rollin and White's invention, which they patented, so the company, after his death, played catchup with their designs.

The Thuer was first and not really successful for it's cartridge design and was soon unnecessary as Grant did not renew Rollin and White's patent so Colt then applied the concept to their existing designs.

This creates a number of "work arounds" which Colts accomplished by making huge changes to the revolver. The 1851 Navy has plenty of working room in the design but the already taxed 1860 Army gets very close to the design limitations. Eventually Colts moves onto a newer design eliminating the frame modifications with the advent of the 1871/72 open top. The Open Top, in very short order, becomes obsolete with the advent of centerfire ammunition so they design the 1873 SAA Army revolver.

[Thumper]

Thanx...lot's of good info on those post's

[Pettifogger]

GREAT photos.  Now just add a photo of a single tooth hand and a double tooth hand and everyone should get the picture.  With a big wide ratchet with teeth on center line a hand with one tooth could do the job.  Not so with skinny teeth set off center.  You need the second tooth to complete the cylinder rotation.  Again, these are great photos.

[Hoof Hearted]

GREAT photos.  Now just add a photo of a single tooth hand and a double tooth hand and everyone should get the picture.  With a big wide ratchet with teeth on center line a hand with one tooth could do the job.  Not so with skinny teeth set off center.  You need the second tooth to complete the cylinder rotation.  Again, these are great photos.

Sure, I'll try to get some pics and add to the post............but HOPEFULLY I made my point with this post and it won't turn into "can you measure how much to mill off the recoil shield of my frame" and "why can't you make me a one off cylinder for 50 bucks" thread

Regards, HH

[Pettifogger]

Sure, I'll try to get some pics and add to the post............but HOPEFULLY I made my point with this post and it won't turn into "can you measure how much to mill off the recoil shield of my frame" and "why can't you make me a one off cylinder for 50 bucks" thread

Regards, HH

Can you?   

[Coffinmaker]

.45 ACP cylinder for 50 bucks ..... Right?? After all, Look Ma, No Rim 

Coffinmaker

[Professor Marvel]

Now just add a photo of a single tooth hand and a double tooth hand and everyone should get the picture.

here you are:

single tooth


double tooth


yhs
prof marvel

[Colt Fanning]

Howdy,
The ratchet might be moved to a position between the chambers by the trick posted to the "Recut Ratchet" post in
the gunsmith forum.  (I haven't tried it.)  But the problem of the very thin cylinder walls at the bolt notches still
remains.
Regards
Colt

[Long Johns Wolf]

Great pics & information!
Long Johns Wolf

[Thumper]

Professor Marvel, the only 2 gun types I have worked on with the double toothed hand are the Colt 1877 (Lightning & Thundered) and the Merwin Hulbert 32 dbl action, who else used this configuration and in what models, thanx.

[Pettifogger]

Professor Marvel, the only 2 gun types I have worked on with the double toothed hand are the Colt 1877 (Lightning & Thundered) and the Merwin Hulbert 32 dbl action, who else used this configuration and in what models, thanx.

Virtually every single action revolver and most of the double actions made in the cartridge era uses two teeth.  The easier thing would be for you to identify those that don't.