RE: 44-40 questions
The .44-40 was developed for use in the 1873 Winchester rifle.It was the most popular caliber chambered for that rifle. It was used in some Marlin rifles. It was also used in pump rifles made by Colt, and Remington.
The .44-40 case is slightly bottlenecked and is larger in diameter than the .44 Magnum: The .44 Magnum case is straight.