While the Colt .38 LC revolvers in military service were technically replaced by the Colt .45 M1909 New Service revolver (a stopgap for use in the Philippine campaign as the .38 LC revolvers couldn't cut in combat with the Moros) and later by the .45 M1911 pistol, the old revolvers soldiered on through WWI. However, they were normally relegated to use only in rear areas where they weren't likely to see combat action. Even after WWI, the .38 Colts continued in use into the 1920s by various state guard units. Most .38 LC ammunition for them was purchased before, during, and after WWI by the Army from commercial sources as Frankford Arsenal had better things to do than making obsolete cartridges for an obsolete military revolver. Military .38 LC ammunition having Remington, Winchester, Peters, and U. S. Cartridge headstamps is fairly common in collector circles. The ammunition was commercially loaded in the U.S. until around the late 1970s and I have several boxes of Winchester .38 LC ammunition I bought at that time in my collection. I think there are still some small custom loaders still selling .38 LC. It is fairly simple to make it yourself - just cut .38 Special cases shorter. But few need any.