The 38-72 WCF (Winchester) was designed for, and introduced with, the Winchester Model 1895 lever action, box magazine repeater. It�s a nearly straight case with a very slight neck. The 38-72 case has the same basic body as the 30-40 Krag, but because headspacing is on the rim, it may not be possible to safely use that case to make 38-72, except for very low pressure loads. 

This text is based on information from “Cartridges of the World”, Hodgdon reloading manual, the cartridge designer and/or own resources.