If not the earliest, the 38-40 WCF is certainly among the earliest chamberings one could reasonably refer to as a factory wildcat. Winchester introduced it in 1874, the year after it introduced the 44-40 WCF. Chambered in the same Model of 1873 Winchester rifle and then the Model of 1873 Colt Single-Action revolver, the 38-40 with the original blackpowder load launched a 180-grain bullet at about 1125 fps from a carbine and about 975 fps from a revolver. This represented revolutionary handgun performance in that era. While not much faster than the 45 Colt load, the lighter bullet generated far less recoil and many shooters gravitated to the 38-40 as a single round they could use in their Winchester and Colt guns. It is interesting to note that original 38-40 and 40 S&W ballistics are practically indistinguishable. Improvements in bullet design likely make the modern round more effective as a fight stopper but loaded with the Lyman 180-grain SWC (long-discontinued), the 38-40 remains serious medicine. Two other interesting points about the 38-40: first, Winchester deliberately bastardized the naming to indicate propellant-charge and then caliber, rather than caliber and then propellant-charge, as was the convention. Then as now, marketing matters and 40-38 simply does not roll off the tongue, while 38-40 has a pleasing ring to it; second, the 38-40 might well hold the distinction of being the most difficult cartridge to handload. Part of the latter problem stems from the unusually thin case necks, the remainder stems from the fact that many early die sets had only two dies, offering the handloader no means of belling the case mouth, which is essentially necessary because of the unusually thin and weak case neck. With a three-die set, such as Lee sells, it is possible to handload the 38-40 with precision and without ruining cases, bullets, and fingers. I cannot too-strongly recommend getting a second seating-and-crimping die so you can have one adjusted to only seat the bullet and the second adjusted to only crimp the case mouth. I can attest that attempting to do both operations in one step is a recipe for damaged and destroyed cases. The other issue with the 38-40 is the wild mismatch between the chamber and factory-loads or resized cases. Typically, the fireformed case has a very-short neck, while the resized case has a very-long neck. Therefore, each firing and reloading of the case dramatically work hardens it. Case life without careful annealing is very short. Adjusting the sizing die out until it only resizes the case enough to freely fit the chamber can substantially improve case life and accuracy. The problem with this approach is it results in a relatively short neck that can limit bullet pull, which can reduce accuracy and possibly lead to recoil pulling bullets from cases and jamming the revolver after one or more shots. Use of Starline cases helps because the necks tend to be about 5% thicker than the necks on Winchester or Remington cases. Modern revolver-smiths, such as the late John Linebaugh, have built modern five-shot revolvers chambered for the 38-40 but using a properly designed chamber, to allow resized cases to fit while providing all the neck tension possible with the thin case neck. Loaded with modern propellant to maximum feasible pressure in those high-strength revolvers and the modern version of the Marlin 1894, such loads can rival energy of the 44 Magnum while generating significantly less recoil. Of course, it is hypercritical that no such ammunition ever finds its way into any standard 38-40 gun. Historically, it has been very hard to find any smokeless load combination that generates great results with standard pressure. The introduction of Trail Boss solved this problem; just fill the case to the base of the bullet and use the Remington 2½ primer, you will have a fine load. (Handloaders can duplicate the old Winchester High-Velocity factory load for use in the 1892 Winchester and other strong guns; performance of such loads are in an entirely different class.) As with all cartridges used in guns with a tubular magazine, a properly applied crimp can smooth and ease chambering and a crimp is critical to lock the case mouth into the cannelure and thereby prevent recoil and chambering forces from driving the bullet into the case. In some instances, a roll crimp might be the best option But the Lee Factory Crimp Die usually does a better job and the crimp it applies will not damage a cast bullet as chamber pressure drives that from the case.