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Old August 30, 2011, 03:15 PM   #1
Billy Shears
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Cartridge Conversion Cylinder Question

Can someone help me out here?

I’m considering a conversion cylinder for an 1860 Army so I can shoot .45 Colt ammo, of which my basement is stocked with many hundreds of rounds.

I’ve searched other threads and found some good information, but I’m still not completely satisfied that I understand the situation.

As I understand the instructions that come from Howell’s and Kirst, anyone who uses their conversion cylinders is cautioned to use either black powder loads or “cowboy” level smokeless loads, whatever those are.

I think I understand the reasons why smokeless loads should be kept toned down to “cowboy” level. Unique powder, for example, is a fast burner, and even a small charge, say 7.5 – 8.0 grains or so, can cause high pressures when loaded behind a 255 grain round nose flat point .45 caliber bullet. However you measure it, it’s a potent load.

What I don’t quite understand though is why the conversion cylinder makers say .45 Colt black powder loads of a similar strength are ok. Or, to be more precise, why they don’t issue more specific warnings about BP loaded cartridges.

I know this is kind of convoluted so I beg your patience, but this is what I’m seeing. A traditional cap and ball load for an 1860 Colt is a roughly 140 grain lead round ball over 25-30 grains of black powder. This produces something along the lines of .38 Special power.

The original .45 Colt black powder load however was a 250 or 255 grain bullet over 40 grains of black powder. Out of the 7.5 inch barreled Single Action Army revolvers, according to Duke Venturino, these produced 950 fps and in excess of 500 pounds of energy. Literally a “horse pistol” load. The 1860 Army has an 8 inch barrel and would presumably produce similar velocities with similar loads.

This is way beyond “cowboy” level ammunition. Seems like just running the numbers, even a .45 Schofield black powder cartridge [250 grain bullet over 28 grains of BP] would be far more powerful than the original cap and ball loads and a step or two above smokeless “cowboy” loads too.

How is it then that the conversion cylinders are rated to fire such heavy black powder loads, but users are cautioned strongly against smokeless loads moving at similar velocities?

Seems to me like this can’t be simply a pressure problem, but what do I know? Is it frame stretching? Or parts breakage? Or what? All I’m thinking is that if the revolver can stand it, these black powder cartridges would be great for a camp or woods gun.

So, I guess my long-winded round-about question is…is it dangerous or unwise to fire a steady diet of these BP cartridges out of an 1860 Army revolver with a conversion cylinder?

Am I risking catastrophic failure, early and unnecessary parts wear, or some other unknown complication?

Or is it entirely OK to do this and I’m just being a Nervous Nelly?

Any info appreciated.

Thank you.
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Old August 30, 2011, 05:26 PM   #2
Ideal Tool
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Hello, threedog. Before I purchased a Kirst, I had a very long phone conversation with Mr. Kirst. He said these cyl. are proofed to be safe with any std. velocity smokeless load..not +p..but normal lead-bullet loads.
I can understand your confusion...But it is not the cyl. that you should be worrying about..and the reason they caution about pressure...It's that mid-19th. century, three-piece-held together by a wedge design that they are concerned about. Mr. Kirst said he has had numerous revolvers sent in with cyl. arbors pulled forward out of frame. From firing with heavy smokeless loads. This then is the main reason for sticking with the lighter loads in these open tops.
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Old August 30, 2011, 05:47 PM   #3
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Jacketed ammunition?

I have heard people on various survivalist forums say that they fed Golden Sabers and other factory jacketed ammo through the Kirst converted Rems with no problem at all. What does the hive say here? This is the first time I have heard of jacketed ammo being used in these revolvers.

Me, I used nothing except pure cast/swaged lead loaded with BP or substitute. Could the above about jacketed stuff be dangerous misinformation?

Lets get this clarified here too.
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Old August 30, 2011, 06:39 PM   #4
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Originally Posted by threedogdad
So, I guess my long-winded round-about question is…is it dangerous or unwise to fire a steady diet of these BP cartridges out of an 1860 Army revolver with a conversion cylinder?

Am I risking catastrophic failure, early and unnecessary parts wear, or some other unknown complication?

Or is it entirely OK to do this and I’m just being a Nervous Nelly?
You might want to read the Wiki page on the .45 Colt cartridge.

I quote: "The .45 Colt originally was a blackpowder cartridge, but modern loadings use smokeless powder. The original blackpowder loads called for 28 to 40 grains (1.8 to 2.6 g) of blackpowder behind a 230-to-255-grain (15 to 16.5 g) lead bullet. These loads developed muzzle velocities of up to 1,000 ft/s (300 m/s)."

There are a number of us who like to load up .45 Colt with 250 grain lead bullets on top of 40 grains of FFFg BP just for grins. As you can read from the Wiki quote a typical .45 Colt load was generally 28 to 40 grains of BP. I would consider these loads to be within the "cowboy load" range.

So, to answer your questions....No, it is NOT dangerous to fire a steady diet of BP rounds through your revolver configuration. At least that is my opinion but you know what they say about those.

Assuming your converted revolver is a modern steel replica and in good working order (you should always monitor/inspect a firearm as you shoot it) I don't see any particular issues arising from the BP cartridge loads. This of course assums proper loading with good brass, gapless BP loads, and the proper lead bullet. Do NOT use jacketed bullets just soft lead 0.452.

Absolutely nothing wrong coming in here as a nervous nelly and asking any question on this topic. Better safe than sorry. That is what these forums are for.

BTW, it is likely that you will want to load your .45 cartridges with 30 - 35 grains of BP most of the time. For most people 40 grains BP under a 250 grain RNFP lead bullet is just for -CENSORED--CENSORED--CENSORED--CENSORED--CENSORED-s-n-giggles as 30 -35 grains makes for a nice .45 Colt load. Besides, without a drop tube and/or a compression plug 40 grains is a bit of work to fit into .45 Colt brass but it is do-able with the right tools.
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Old August 31, 2011, 06:30 PM   #5
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It's not about FPS or power - smokeless has a different type of pressure/pressure curve than does BP, ergo the caveat of conversion cylinders for Cowboy loads and "no brass framed revolvers".

Yes, I'm sure we all know somebody like Schrapnel, who's "done it" w/o problem - but it's always that "next" shot, when a problem could literally explode upon the scene.

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Old September 1, 2011, 05:55 AM   #6
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All of this is so true. I have a Uberti Walker and made a conversion cylender and loading gate for it copying an orignal and using hardened modern gun steel, it is chambered in 460 S&W but I only shoot BP 50 grains yet after presure tests I noted that the presure in a cartridge conversion went UP about 20% over the same bullet seated inside the original cylender of the revolver using the same powder load.
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