This article explains why original lever guns were never chambered in 45 Colt. Mainly, it's because Colt owned the patent and wouldn't allow it. I wonder if they had worked out a deal with Winchester, maybe Winchester paid them a royalty or scratched Colt's back some other way if the U.S. army might have looked at the lever rifle differently being chambered in a caliber they already had in their supply chain? (Yes I know about the 45 Schofield but the rifles work with those too; or at least my Uberti Henry does.)
Howdy
That is indeed an excellent article, particularly with his reference to the 45 Colt being a proprietary round. I don't know if that is true, but it is very interesting.
However the article overlooks, or at least does not make much of, a couple of other factors relating to the lack of rifles chambered for 45 Colt until relatively recently.
The first has already been touched on here. The rims of early 45 Colt ammunition were tiny. Being developed for a revolver, there was no need for a large diameter rim because the empties were punched out of the chambers by an ejector rod from the inside. There was no extractor on the Single Action Army, never has been. All the rim had to do was prevent the cartridge from being shoved into the chamber when struck by the firing pin, and it did not take a very wide rim to do so.
Here is a photo of some old 45 Colt rounds. Notice the majority of them have very small diameter rims. (except the round second from the right) Notice too, there are no 'extractor grooves' on any of these rounds except the modern round all the way on the right.
Here is a close up of two of the rounds. The round on the left is typical of the original configuration of the 45 Colt round. It is a copper cased, Benet Primed round made at the Franford Arsenal in 1874. The two dents near the bottom hold the anvil plate of the inside priming in place. The diameter of this rim is only .503, barely larger than the body of the cartridge. This worked fine for a revolver like the SAA which punched the empties out from inside, but the extractor of a rifle would have had nothing to grab onto.
The round in the middle is a Winchester Repeating Arms round. The rim on it is only .505 in diameter, still not large enough for a rifle extractor to get a good purchase on.
The round on the right is a 44-40. Notice the rim is much larger, .525 in diameter. The 44-40 was designed specifically as a rifle round. The rim was made large enough so that a rifle extractor could get a good purchase on it.
Current SAAMI standards for the rim diameters of 45 Colt and 44-40 are .512 for 45 Colt and .520 for 44-40. A .512 diameter rim is large enough that a rifle extractor can grab it.
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Regarding 'blowby' and 45 Colt rifles.
No, it is not specifically restricted to Black Powder loadings, I have seen gas jetting out of the top of the action of a 45 Colt rifle at CAS matches, but it is not much of an issue with Smokeless powder. It becomes an issue with Black Powder.
The reason for blowby with 45 Colt is because the case walls are thicker than cases such as 44-40. 45 Colt brass tends to run around .012 thick at the case mouth, 44-40 tends to run around .007. Some folks think it is the tapered shape of the 44-40 or 38-40 that keeps fouling from blowing by these rounds, but that is incorrect. It is the thickness of the brass. With the relatively low pressures developed by Black Powder, or light Smokeless charges, the thin 44-40 brass expands and seals the chamber, keeping the gases, and fouling pretty much in the bore, where it belongs. However these same pressures are often not able to expand the thicker 45 Colt cases enough to seal the chamber, so some gas tends to make its way back out of the chamber and into the action.
Not much of a big deal with Smokeless, just some gas back into the action. But with Black Powder you can get fouling into the action and it can bind up the action in relatively short order.
There are workarounds. Most of them involve raising the pressure so the 45 Colt seals better in the chamber. This can be done by always using a heavy bullet, such as 250 grains. Being sure the crimp is heavy will also help raise pressure. And lastly, some folks only neck size their 45 Colt brass, so the main body of the round remains in an expanded state to better seal the chamber. This may not be a good idea if the brass is to be used in more than one rifle, the chambers may not be the same.
My first CAS rifle happened to be an original Winchester Model Model 1892 chambered for 44-40. So I developed an affinity for the cartridge. Later on I started loading it with Black Powder. At this point I have I think five rifles chambered for 44-40 and one chambered for 38-40. When I fire these rifles, the brass ejects almost as clean as it went in, with very little fouling on it. Almost all the fouling stays in the bore where it belongs.
