With the Model of 1873, Winchester was able to address the major remaining weakness of the Henry and 1866 rifles – the cartridge. The 1873 was introduced in tandem with the .44Winchester Center Fire cartridge (known more commonly today as the .44-40). This cartridge kept the 200 grain bullet from the .44Henry Rimfire round, but used a brass case (as opposed to copper) and was able to increase the powder charge from 28 grains to 40, for a substantial increase in velocity.
In addition, the Model 1873 used a lighter steel frame and introduced a sliding dust cover on the top of the action to help keep out dirt and debris. The centerfire nature of the cartridge made it possible to handled ammunition when a commercial source was not available (Winchester sold the reloading tools). The 1873 was available with a wide variety of options, including barrel and magazine lengths, buttstock and grips, sights, and fancy options like engraving. It would prove to be a massively popular weapon both in the United States and abroad, cementing Winchester’s position as the premier manufacturer of American repeating rifles.