The .25-20 Winchester, or WCF (Winchester center fire) was developed about 1895 for the Winchester Model 1892lever action rifle. It was based on necking down the .32-20 Winchester. In the early 20th century, it was a popular small game and varmint round, developing around 1460 ft/s with 86 grain bullets.
While the SAAMI pressure rating is a full 28,000 CUP, modern ammunition is often loaded lighter in deference to the weaker steels used on many of the original guns. The early black powder cartridges were loaded to about 20,000 psi, but the SAAMI rating is close to that of the high velocity smokeless rounds produced later. The high velocity loadings developed 1732 ft/s.
It was easy and economical to reload, and was once a favorite with farmers, ranchers, pot hunters and trappers. Though the .25-20 has been used on deer and even claimed a whitetail deer of long standing record in 1914, its use on large-bodied game is not advised due to its sedate ballistics and light bullet construction, which makes humane one-shot kills unlikely.