44-40, or better said, the 44WCF

Over the years, the concept of the rifle cartridge underwent significant changes, from the paper wrap, which brought us the term..."keep your powder dry"...to the copper, then brass, and today's plastic coated steel cases. 
The venerable 44 Winchester Central Fire , WCF, was by far the most successful rifle cartridge of the 19th century. Remembered today as a quaint revolver loading, the 44WCF was the companion of scouts, hunters, prospectors, and Indians across the last decades of the American frontier. It made its name with black powder and cast lead, the primary offering in the Winchester 1873, the first successful centerfire repeating rifle.
The 44WCF made its transition into handguns soon after it's debut. Merlin & Hulbert, Remington, and perhaps most famously Colt lead the charge, and the world never looked back. They were joined by others, including British imports, and soon the 44WCF was international.
It is now rare to find the venerable 44 chambered in its original long gun configuration. It's transition to smokeless powder was far from seamless, and indeed for most who shouldered such a weapon went looking for more power. Factory smokeless offerings were indeed on the anemic side, but for a few higher pressure flings across the decades. The thin bottleneck cases, which worked so well with black, would separate at the neck if too much was demanded. The solution was a general step down in intensity, and the 44WCF became the forgotten cartridge until the advent of cowboy action.
I was one of the few who took kindly to the original WCF. In a 4 3/4" SAA the cartridge was so accurate, it made difficult shots all too easy. FFFg filled the case, and the flat nosed slug just set right on top of that charge. In the rough conditions of the remote mountains, the old 44 was right at home.  
There is a lot of mystique today around super powerful bear guns and loads. For some reason folks seem to think a wilderness cartridge needs to be a howitzer. I don't think these people ever spent much time on the land, because other than for stopping a runaway pickup truck, the howitzer is completely useless for most things you need a gun for, and that translates into the vast majority of anything one might run across. I hated saying goodbye to that old Colt, and to this day I wish I still had it slung comfortably in the worn crossdraw holster it called home.
The 44 made a boom that broke up dog fights, warned ne'er do wells, and signalled friends. It could punch a clean hole through a stock gate that made the wire tensioning simple. It's presence was so much more than the one dimensional thinking one finds associated with revolvers today.
I'm glad for the aficionados of SASS, because it surely was due to them that the old 44 is still available today. A rifle cartridge now mostly found in revolvers, it has its own thoroughly unique history and appeal.