Initially, the company was plagued by sluggish returns, which was in part attributed to the design and poor performance of the Volcanic cartridge: a hollow conical ball filled with black powder and sealed by a cork primer.

Henry sought to improve on the Volcanic repeating rifle by enlarging the frame and magazine to accommodate seventeen of his newly redesigned, all-brass cased .44 caliber rimfire cartridges.

In 1866, employee Nelson King's new improved patent remedied flaws in the Henry rifle by incorporating a loading gate on the side of the frame and integrating a round sealed magazine which was covered by a fore stock.

[3] Oliver Winchester was also active in politics, serving as a New Haven City Commissioner, Republican Presidential elector in 1864, and as Lieutenant Governor of Connecticut from 1866 to 1867.

William's wife, Sarah, moved to San Jose, California, where she began building a chaotic mansion now known as the Winchester Mystery House with her inheritance.