.44 Thuer case (Sectioned)

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.

Further research on the construction of the Thuer case. In a couple of Buttweiler catalogs, he indicates that the primer assembly, or anvil, is inserted (not screwed) into place from the inside and held in place by a flange. This flange is apparently forced down against the primer assembly as it is pushed into position in the head of the case. The sectioned cartridge from Suydam’s book shows this fairly well, though it also appears to show screw threads.


Thuer revolvers were before my time so I’ve never paid too much attention to them or the cartridges. Your photos are the first I’ve seen that really show their construction. But, I’ve always had this dumb question - what holds the cartridge in the cylinder? In other words, what keeps the whole thing from moving forward from the hammer blow?


Ray, a thing called friction :-). Thuer hoped that obturation would do the job durnig firing. Had a collector friend who just passed away show me the operation of a Thuer. He said he had fired a few rounds in his pistol and one chamber would never eject the spent shell the first time. Really an interesting set up but also Mickey Mouseish


Essentially, it was supposed to work the same as loading a paper cartridge in a percussion revolver, with the cartridge being forced back into the tapered chamber using the loading lever, and the resulting tight fit of the ball in the chamber holding everything in place. It just didn’t work as effectively, because the percussion cap was attached to the cartridge rather than fixed to a nipple on the cylinder. As a result, any forward movement of the Thuer cartridge resulting from recoil or mishandling of the pistol risked moving the primer too far forward for the firing pin to make contact.

Remember, this whole Rube Goldberg scheme was not selected for its marginal technical merits, but as a way for Colt to sell cartridge revolvers without infringing on the Rollin White patent for “bored through cylinders” held by Smith & Wesson.

The whole topic of “S&W Evasion” cartridges wouild be a fascinating story for a Journal article, kept at a fairly basic level.

Anyone? Anyone?

If someone has some sectioned examples of S&W evasion cartridges, I would be glad to run one or a grouping as the “Cartridge of the Month”. PM me if you have anything to submit.

Mighty interesting. Do we know if the Thuer primer is the same dimensions as any of the standard percussion caps, or is it unique? It certainly looks rather small in the flesh and in the above illustration. Anyone got a tin of Thuer primers handy? JG

I don’t have a loose primer, but measuring it on the cartridge shows it to be about .165", though its tough to get an accurate measurement. The lower tin in this picture is for Thuer cartridge primers; unfortunately, its empty. There’s no mention of Thuer on its label. I suspect that is due to the fact that Thuer patented the revolver conversion process and but did not patent the cartridge. I’m not sure what the upper tin is for; the top has been removed in the picture to show the tiny primers that are in it. I had originally thought these were for the Thuer cartridges, but they are too small, and the lack of ‘Central Fire’ on the label leads me tho suspect they are pinfire shotshell primers.

Guy: Another mystery better understood now. Thanks again. JG