.38-40 Winchester (Rifle)
Date: Dec 23 2014
Notes from the Lab: .38-40 Winchester (Rifle)
The .38 WCF, or .38-40 Winchester, was developed around 1874 for the Winchester Model 1873 lever-action rifle. Although its name is confusing, it is actually a .40 caliber. It quickly became popular in a variety of rifles and revolvers and during its heyday was considered suitable for deer or defense. Originally it was a black powder cartridge, and early guns (those in good condition) should only be used with black powder loads rather than the smokeless loads presented here. Be certain a gun is intended for smokeless powder before using these loads.
Today’s Winchester factory loads advertise a 180-grain JSP bullet at 1,160 fps, with the test rifle used here reaching 1,157 fps average for a five-shot string.
The accompanying data contains Hornady jacketed bullets designed for the .40 S&W and 10mm Auto cartridges. They do not have a crimp cannelure as they are intended for a taper crimp that is commonly applied to auto-loading pistol cartridges. When loading these bullets in the .38-40, only a light roll crimp can be applied. To improve bullet pull, accuracy and consistency, it is suggested to apply a cannelure to the bullet using a C-H tool, then crimp them rather gently with a roll crimp. The Lee Precision Factory Crimp Die can also increase the crimp without causing the case to buckle. Starline cases were used exclusively in developing the accompanying data.
Oregon Trail 180-grain RNFP cast bullets feature a deep enough crimp groove to allow a suitable roll crimp; however, the case is thin and the crimp should be applied with care to prevent case buckling.
The .38-40 is a relatively low pressure cartridge with industry maximum pressures established at 14,000 cup. Many of the "start" loads only produce around 10,000 psi. To prevent bullets from sticking in the bore from too little pressure, a potentially dangerous situation in any gun, it is strongly suggested that "start" loads are not reduced.