Another point I don't believe has been made
is that the "steel" of the middle/late 19th
Century was more iron-like and soft, the
strength no where near today's steel.
Breakage was much more prone. I have
a very good gunsmith friend who has mentioned
this when working on 19th century firearms
and even those well into the 20th.
Howdy Again
Here are some quotes from Kuhnhausen's
The Colt Single Action Revolvers, A Shop Manual, Volumes 1 & 2, regarding the materials used for Colt SAA frames and cylinders:
Frame Material Notes: mid page 70:
1. Early black powder model S.A.A. frames up to about s/n 96,000 (up to about mid 1883) were made of malleable iron.
2. Intermediate S.A.A. frames between approx. s/n 96,000 and 180,000 (mid 1883 to mid 1898) vary but were apparently made of transitional materials generally similar to modern low-medium carbon steels. The lowest carbon content found in intermediate s/n S.A.A. frames tested to date is approx. .0155, indicating the possibility that early formulations of 1015~1018, or higher carbon type steels may have been used in many frames of this era.
3. Although there are exceptions, frames manufactured after s/n 180,000 appear to have been made from medium range carbon steels. The lowest carbon content found in the after s/n 180,000 frames tested was approx. .0213, possibly indicating that 1020~1027 or slightly higher, carbon, or similar steels may have been used in these frames.
Bottom of page 71:
(1) 1st Generation S.A.A. cylinder material changes began to occur at about the same time that S.A.A. frames were being metallurgically updated. Cylinders prior to approx. s/n 96,000 (mid 1883) were made from materials generally resembling high grade malleable iron. Original cylinders from approx. s/n 96,000 to about 180,000 (mid 1898) were made from transitional low/medium grade carbon type steels. These cylinders and their parent frames were not factory guaranteed for smokeless powder cartridges. Cylinders after frame s/n 180,000 (mid 1898) began to be made from medium carbon type steels. Later versions of these cylinders were better and more uniformly heat treated. S.A.A. revolvers with cylinders of this final type were factory guaranteed in 1900 for standard factory load smokeless powder cartridges.
(2) 1st Generation 357 Magnum cylinders were made from fine grade, higher tensile strength ordnance quality gun steel. These cylinder blanks, identified by a 5 pointed star imprinted on the front, turn up on other caliber S.A.A.’s made during, and after 1935. (The 357 Magnum was introduced in 1935.)
So as Kuhnhausen noted, very early SAA frames and cylinders, up to 1883, were not made of steel at all, rather they were made from malleable iron. Just as the cylinders and frames were in all the early Colt Cap & Ball revolvers.
Don't be confused by the term malleable iron. Not the same as cast iron or pig iron, malleable iron was iron that had all the impurities removed, and as the term denotes, it was malleable, meaning it could be heated and 'worked', or hammered into shape. Cast Iron and Pig Iron, such as a blacksmith's anvil is made from, cannot be 'worked'. These forms of iron have impurities left in them from the casting process and have much lower tensile strength than malleable iron. Malleable iron was not as strong as the steels that Colt was using later on, but it was plenty strong enough for the frames and cylinders of the Black Powder era of cartridges.
As a side note, the iron cylinders of the Colt Walker model are often blamed for the few surviving examples. Iron cylinders, coupled with the Walker Colts enormous powder capacity, close to 70 grains if I recall correctly, often resulted in the cylinders blowing up.
