1860 Army, point I hadn't thought of

[unspellable]

Just acquired a Pietta 1860 Army. On giving it a good look over, I began to wonder why the rebated cylinder. (I'd know long ago it was rebated but never gave it much thought.)
The chamber goes all the way into the rear rebated part. If the rebated part is strong enough, why did they make the front of the cylinder larger? Seems pointless.

 

[Mike 56]

Colt wanted to use the same frame both 36 and 44cal with just the water table milled differently. He did the same thing with the 36cal pocket pistols.

 

[unspellable]

Enlarging the front of the cylinder adds a step to making the cylinder and adds a step to making the frame. But if the rear of the cylinder is big enough, why enlarge the front?

 

[entropy]

Because it simplifies making the frame; As mike 56 said they just milled out more of the water table, (the part of the frame that is under the cylinder) of the 1851 Model initially, then when they introduced the 1860, which was designed as a .44, they made that part of the frame the same way so they could make it either caliber.

 

[unspellable]

You guys don't get the question at all! Forget the frame. Why is the front of the cylinder LARGER than the rear? If the rear is strong enough, why make the front larger?

 

[expat_alaska]

When Colt started designing a new, lighter .44 caliber revolver around 1858 to replace the heavy (4lbs.-2 oz.) 3rd Model Dragoon, he first created several prototypes using lighter cut-down Dragoons. Most were fairly ungainly looking, did not remove enough weight to suit his purposes, so he put his efforts into using an 1851 Navy frame. The .36 caliber cylinder when bored to .44 caliber did not have enough steel to safely contain the charge without rupturing the chambers, so the "New Model Army" was based on an 1851 Navy frame with the water table cut down, as the previous poster mentioned. The first several 1860 Army cylinders were full-fluted in order to cut down more on theweight of the revolver, but a fair amount of them ruptured near the rear of the cylinder (especially around the stop slots) because the chambers were bore straight down to the front of the nipple in .44 caliber. Colt then decided to use the rebated engraved (Colt trademark) with a cylinder he termed as the "cavalry cylinder". The chambers were bored at .44 caliber down to where the rebated line stops and then it tapered down to .36 caliber so there was the same amount of steel at the rear of the cylinder as the Navy .36 caliber cylinder.

If you have a copy of Charles W. Pate's excellent book "The Colt Model 1860 Army Revolver" there is a drawing and description of this on pp.134-135.

I like the look of the 1860 Army full-fluted cylinder, so after careful measurements I bought a new 2019 Uberti cylinder for my Armi San Marco 1860 Army .44 datecode BD/1994. It fits like a glove with a .003" barrel/cylinder gap and the chambers line up perfectly both vertically and horizontally with the barrel forcing cone. It cost $100 from Taylor's and I bought the revolver used about 18 months ago for ~$200.



I then came upon a cased set with shoulder stock and accoutrements but it had a Pietta 1851 Navy .36 4-screw CFS for $450 last January. The stock J-hook and housing was too large for the Navy gripframe, so after repairing the case dividers I substituted the 1860 in place of the 1851. It worked out well for me.





Regards,

Jim

 

[Ed Ames]

You guys don't get the question at all! Forget the frame. Why is the front of the cylinder LARGER than the rear? If the rear is strong enough, why make the front larger?

Think about it the other way around. They made the rear smaller so everything would line up the same as a .36. As far as strength, I don’t know about the historical guns but at least some of the modern ones have a step in the chamber so the wall thickness stays the same. Basically, they do the .36 boring to full depth and then the .44 boring to partial depth.

 

[unclenunzie]

I think I see what you're after, but it looks like they start with a cylinder that is the size of the front (larger) all over, then mill/machine the rear. Why, I do not know, just looks like that to me.

 

[entropy]

You guys don't get the question at all! Forget the frame. Why is the front of the cylinder LARGER than the rear? If the rear is strong enough, why make the front larger?

No, you don't understand the answer. The Colt 1851 was originally designed as a .36. The Army specified .44 at some point (not sure what year), and it was easier for Colt to make larger cylinders to accomodate the difference in diameter between .36 and .44, and then cut away the water table to accomodate the larger diameter. When they designed the 1860 Army, although it was designed as a .44, they retained the same setup as on the 1851. The reasons are twofold; they could use the same frame, and at some point later (two years later, it turned out to be.) they would be able to make a .36 version of the 1860.

What about that do you not understand?

 

[unspellable]

The stepped cylinder and frame add manufacturing steps so they have to be justified. expat_alaska provided the the only answer here that actually addresses the question. If on the original Colt the rear portion of the chamber was smaller, that explains a lot. On my Pietta, the chambers look to be straight 44 all the way down. I presume modern steel allows them to get away with that.

 

[entropy]

Time line:
1851 -Colt comes out with the 1851 .36 revolver to meet a US Navy specification.
Sometime between 1851-1860, closer to 1860; The US Army, requires the gun to be .44 (Remington built a whole bigger gun to meet this requirement.)
Colt redesigns the cylinder of the 1851 to have a larger chamber, but retains the size of the 36 at the rear to utilize off-the-shelf parts. This new cylinder requires the water table to be milled down in the front. Concurrently or shortly afterward, Colt redesigns the barrel assembly to ease reloading (An area where the Remington 1858 was easier to use), changes the grip frame, and some other small changes, and comes out with the Model 1860.

As for the chamber going all the back, yes it does. but it reduces in diameter past a certain point.

 

[SC45-70]

You guys don't get the question at all! Forget the frame. Why is the front of the cylinder LARGER than the rear? If the rear is strong enough, why make the front larger?

The front of the cylinder needed to be larger to accept the 44 cal bullets, the full bore diameter of the cylinder starts after the step. The nipples screw into the rear of the cylinder up to the step so the rear of the cylinder only needs to be large enough to accept the nipples.

SC45-70

 

[StrawHat]

The chambers were bored at .44 caliber down to where the rebated line stops and then it tapered down to .36 caliber so there was the same amount of steel at the rear of the cylinder as the Navy .36 caliber cylinder.

That right there is the reason. Being able to use the Navy frame was a bonus. Colt’s “Silver Steel” made it possible as it was quite a bit stringer than the wrought iron used prior. And silver steel was steel made by the Bessemer process, had nothing to deal with silver. You’d expect that from a quack medicine man.


Kevin

 

[expat_alaska]

I presume modern steel allows them to get away with that.

You would be correct, but I have measured my Uberti full-fluted cylinder and it is tapered at the rear like the originals. Somewhat historically correct, maybe. I shoot it and it has not blown up yet with 30 grains of BP.

You folks have a good night.

Regards,

Jim

 

[AlexanderA]

The stepped cylinder and frame add manufacturing steps so they have to be justified. expat_alaska provided the the only answer here that actually addresses the question. If on the original Colt the rear portion of the chamber was smaller, that explains a lot. On my Pietta, the chambers look to be straight 44 all the way down. I presume modern steel allows them to get away with that.

The whole premise of your original question is that the chambers are bored .44" all the way to the rear. That's not the case, at least for the originals. Tapered chambers may seem to be straight on visual inspection, but only actual measurement of the internal diameter at the rear of the chambers would settle this for sure.

We know that the original Colts had tapered chambers. Modern reproductions may have tapered chambers, may have stepped chambers, or may simply rely on stronger steel to allow straight chambers. expat_alaska states, above, that the Uberti 1860 uses tapered chambers. I have no idea what Pietta does. You may be right that modern steel lets them take the shortcut of boring the chambers straight. Still, this conclusion has no bearing on the design constraints of the original Colt 1860.

 

[Catman42]

man im glad i have a inquiring mind but not to the point it keeps me awake at night. i was told im simple and boring, im glad i am. a ex wife told me that.

 

[unspellable]

Just for laughs, I thought I'd take the cylinder out and measure the chamber diameter at mouth and bottom. Rub is, I so far can't get the wedge out. Took a mallet to it to no avail. Any tricks short of the hydraulic press I saw mentioned somewhere?

 

[Ed Ames]

Just for laughs, I thought I'd take the cylinder out and measure the chamber diameter at mouth and bottom. Rub is, I so far can't get the wedge out. Took a mallet to it to no avail. Any tricks short of the hydraulic press I saw mentioned somewhere?

Brass punch and a big enough hammer? There are many jobs that a 1lb hammer can do if you really swing it, and a 2lb hammer can do with ease. Support the frame on a block of wood on a bench so it doesn’t just move out of the way of the hammer. Use a second punch to push in the spring. That’s what I’ve done with no harm to the 1860 but someone else may have a better way.

 

[unspellable]

How much difference will depressing the end of the spring really make? Starting to be one of those jobs that take three hands.

 

[Ed Ames]

How much difference will depressing the end of the spring really make? Starting to be one of those jobs that take three hands.

I’ve heard it called a four hands job so you aren’t wrong.

If the spring is shaped right and not hung up, you probably don’t need to mess with it...maybe it will scratch the frame or something but that’s going to happen eventually. But I did watch someone manage to break one, once, while trying to remove a stubborn wedge with a hammer.

 

[Darto]

quick answer:
It looked like there was going to be a civil war and Colt submitted their revolvers to test for a large contract to supply the troops with a hundred thousand pistols.
The US army wanted Colt to make their large Dragoon size .44 bullet (ball) fit into their medium 1851 size frame.
So Colt made the 1860 cylinder the same size as the 1851 cylinder because the new frame had to be same size as the old.
But six .44 balls would be too large to fit into the cylinder.
So they had to enlarge the front half the cylinder to allow the balls to fit.
And keep the back half of the cylinder small so it would fit into the frame.

 

[unspellable]

Finally got the wedge out! Chamber measured 0.4445 inch all the way to the bottom, so it's straight on my Pietta.

Was the original Colt chamber tapered or stepped?

 

[expat_alaska]

Was the original Colt chamber tapered or stepped?

After Colt experienced rear cylinder ruptures on the early full-fluted cylinders, the chambers were tapered at the rear, per my #6 post, called the "cavalry" cylinder by Colt.

 

[Old Stumpy]

I think that I will have a go at explaining this.

1) Firstly Colt was unable to produce a .44 belt revolver comparable in size to the 1851 Navy due to being forced to produce the cylinders out of wrought iron. .44 cylinders had to be Dragoon-sized.
2) The Bessemer steel process in the late 1850s solved this problem, allowing a .44 caliber cylinder to be produced with less metal at the outside of the chamber, and smaller in diameter.
3) Colt contemplated producing an all new .44 frame, but then realized that the steel cylinder could be made only slightly larger in diameter as compared to the .36 caliber cylinder.
4) Since only the front half of the cylinder needed to be this diameter because it did not use metallic cartridges, the rear half of the cylinder could remain the same diameter as the 1851 Navy cylinder.
The .44 bullet or ball could be chambered normally in a .44 chamber and the powder charge could occupy a smaller diameter powder cavity.
5) The stepped cylinder made it possible to use the 1851 Navy frame and internal parts, realizing a considerable savings in manufacture. All that was required was to modify the water table, where no internal parts would be interfered with.
6) Had Colt wished, a .44 caliber Navy barrel could have been easily fitted, as well as using the existing Navy grip straps and grip.
7) Instead, Colt opted for a longer round barrel, creeping loading lever, and longer grip straps and grip.
This both modernized the design and made the revolver appear a bit more powerful as befitting a .44 revolver.
8) Colt used the same trick with the .36 caliber Pocket Navy and the 1862 Police model, both based on .31 caliber frames.

 

[StrawHat]

Just prior to introducing the 44 caliber 1860, Colts was experimenting with a 40 caliber in the 1851. The Silver Steel allowed them to drop the 40 and go to the 44.


Kevin