Here’s something I had never seen before - an empty Thuer case. This one is a .44, and has been fired and reprimed. I got this in a small collection of mixed cartridges I traded for recently, and it gave me a good excuse to examine the Thuer cartridge a little more thoroughly than I had before.
The shot looking down into the case shows fairly clearly the inner structure of the primer assembly that extends about .215" above the inside surface of the head. It has a single ignition hole in its center and a slot that is about .110" deep, forming what appears to be a screwdriver slot. The primer is essentially a small percussion cap, fitting down over a nipple. On page 40 of his book U.S. Cartridges and Their Handguns, Charles Suydam has a picture of a sectioned case that shows the construction of the head. It appears in his picture that the case is constructed of two parts, with the primer assembly screwed into the head from the inside of the case, which would explain the screwdrive slot. While this two part construction is not evident from my example, I can’t imagine that the complex machining of the primer assembly could have been performed in place on the case.
This second picture shows three grooves inside the mouth of the case that are intended to grip the bullet and hold it securely in place.