single action cylinder info?

[lar45]

Hi all, I picked up a single action cylinder on Auction Arms. It looks kind of old and used. It takes a 357 size case and is bored straight through. A 223 case will slide all the way through.
It doesn't look like it ever had the best machineing finish ever.
http://pictures.auctionarms.com/283145012/ccb967dd9e7bdf3c0e30cbea5a94c275.jpg?aa=2005072712 0016
http://pictures.auctionarms.com/283145012/1eef8e85e0a777c06821deba3b0cb1de.jpg?aa=2005072712 0016
I want this to rechamber to a 375 Atomic. 30-30 case cut to 1.3".
I'm wondering about the strength of the metal. I'll rockwell test it compared to a ruger and my bounty hunter for comparison.

Could this have been an old cylinder chambered for a heeled bullet something?
Or one that was just never finished?
Thoughts.

I'm thinking that I will chamber this, but only shoot low pressure loads for now until I find out more about it.

[Buckshot]

...........Who knows? There could be so many scenarios as to the provenance of the thing as to be mind boggling. It may not be heat treated, and who knows what kind of steel it was made out of. I don't know if unfinished firearms parts had to be proofed or go through some inspection in Europe before being shipped here for finishing, but it could be that too.

Maybe it is for an old heeled cartridge. Then too the holes bored in the cylinder might just be the guide holes for a finish reamer? I take it there are no marks on it of any kind?

.............Buckshot

[Bent Ramrod]

As I recall from reading, the bored-thru cylinder was characteristic of the .38 Long Colt cartridge. Writers sometimes worried about this in the old days because it was the exception to the rule where a .357 Magnum could not be chambered in older .38 pistols. The .38 Special chamber would stop the longer case but the .38 Long chamber would not. This cartridge had either a heeled bullet the diameter of the case or (in a later incarnation) an inside-lubricated hollow base bullet.

I don't know how you could determine whether your cylinder is of the later, smokeless-proofed type or the earlier, or whether the factory even made the change in metallurgy/heat treatment for the old calibers like .32, .38 and .44 Colt. I think Kuhnhausen's book made the remark that the black-powder cylinders sometimes had shallower bolt cuts. I have a .32-20 cylinder that looks like that. Yours looks more like the normal size bolt cut, so perhaps yours is a cylinder of later manufacture.

I'm assuming yours is a Colt-SAA size cylinder rather than a larger Virginia Dragoon or Ruger cylinder. Partially finished parts for the Dragoons were floating around the gun shows maybe 10 years ago; these are bigger than the Colt size. Presumably the metallurgy of these would stand up to smokeless pressures, as they were chambered for .357 and .44 Magnum.